diff --git a/src/sfizz/Defaults.h b/src/sfizz/Defaults.h
index 3d85871a..a8578536 100644
--- a/src/sfizz/Defaults.h
+++ b/src/sfizz/Defaults.h
@@ -61,6 +61,7 @@ namespace Default
 
     // Region logic: MIDI conditions
 	constexpr Range<uint8_t> channelRange { 1, 16 };
+	constexpr Range<uint8_t> midiChannelRange { 0, 15 };
 	constexpr Range<uint8_t> ccRange { 0, 127 };
 	constexpr uint8_t cc { 0 };
 	constexpr Range<int> bendRange { -8192, 8192 };
diff --git a/src/sfizz/MidiState.cpp b/src/sfizz/MidiState.cpp
index 31c55d63..0766b5c5 100644
--- a/src/sfizz/MidiState.cpp
+++ b/src/sfizz/MidiState.cpp
@@ -8,10 +8,10 @@ sfz::MidiState::MidiState()
 
 void sfz::MidiState::noteOnEvent(int channel, int noteNumber, uint8_t velocity) noexcept
 {
-    ASSERT(channel >= 1 && channel <= 16);
+    ASSERT(channel >= 0 && channel < 16);
     ASSERT(noteNumber >= 0 && noteNumber <= 127);
     ASSERT(velocity >= 0 && velocity <= 127);
-    channel = translateSfzChannelToMidi(channel);
+    
     if (noteNumber >= 0 && noteNumber < 128) {
         lastNoteVelocities[channel][noteNumber] = velocity;
         noteOnTimes[channel][noteNumber] = std::chrono::steady_clock::now();
@@ -20,9 +20,9 @@ void sfz::MidiState::noteOnEvent(int channel, int noteNumber, uint8_t velocity)
 
 float sfz::MidiState::getNoteDuration(int channel, int noteNumber) const
 {
-    ASSERT(channel >= 1 && channel <= 16);
+    ASSERT(channel >= 0 && channel < 16);
     ASSERT(noteNumber >= 0 && noteNumber <= 127);
-    channel = translateSfzChannelToMidi(channel);
+    
     if (noteNumber >= 0 && noteNumber < 128) {
         const auto noteOffTime = std::chrono::steady_clock::now();
         const auto duration = std::chrono::duration_cast<std::chrono::duration<float>>(noteOffTime - noteOnTimes[channel][noteNumber]);
@@ -34,48 +34,48 @@ float sfz::MidiState::getNoteDuration(int channel, int noteNumber) const
 
 uint8_t sfz::MidiState::getNoteVelocity(int channel, int noteNumber) const noexcept
 {
-    ASSERT(channel >= 1 && channel <= 16);
+    ASSERT(channel >= 0 && channel < 16);
     ASSERT(noteNumber >= 0 && noteNumber <= 127);
-    channel = translateSfzChannelToMidi(channel);
+    
     return lastNoteVelocities[channel][noteNumber];
 }
 
 void sfz::MidiState::pitchBendEvent(int channel, int pitchBendValue) noexcept
 {
-    ASSERT(channel >= 1 && channel <= 16);
+    ASSERT(channel >= 0 && channel < 16);
     ASSERT(pitchBendValue >= -8192 && pitchBendValue <= 8192);
-    channel = translateSfzChannelToMidi(channel);
+    
     pitchBends[channel] = pitchBendValue;
 }
 
 int sfz::MidiState::getPitchBend(int channel) const noexcept
 {
-    ASSERT(channel >= 1 && channel <= 16);
-    channel = translateSfzChannelToMidi(channel);
+    ASSERT(channel >= 0 && channel < 16);
+    
     return pitchBends[channel];
 }
 
 void sfz::MidiState::ccEvent(int channel, int ccNumber, uint8_t ccValue) noexcept
 {
-    ASSERT(channel >= 1 && channel <= 16);
+    ASSERT(channel >= 0 && channel < 16);
     ASSERT(ccNumber >= 0 && ccNumber <= 127);
     ASSERT(ccValue >= 0 && ccValue <= 127);
-    channel = translateSfzChannelToMidi(channel);
+    
     cc[channel][ccNumber] = ccValue;
 }
 
 uint8_t sfz::MidiState::getCCValue(int channel, int ccNumber) const noexcept
 {
-    ASSERT(channel >= 1 && channel <= 16);
+    ASSERT(channel >= 0 && channel < 16);
     ASSERT(ccNumber >= 0 && ccNumber <= 127);
-    channel = translateSfzChannelToMidi(channel);
+    
     return cc[channel][ccNumber];
 }
 
 const sfz::CCValueArray& sfz::MidiState::getCCArray(int channel) const noexcept
 {
-    ASSERT(channel >= 1 && channel <= 16);
-    channel = translateSfzChannelToMidi(channel);
+    ASSERT(channel >= 0 && channel < 16);
+    
     return cc[channel];
 }
 
diff --git a/src/sfizz/MidiState.h b/src/sfizz/MidiState.h
index 02a1a37a..949e0764 100644
--- a/src/sfizz/MidiState.h
+++ b/src/sfizz/MidiState.h
@@ -18,7 +18,7 @@ public:
     /**
      * @brief Update the state after a note on event
      *
-     * @param channel (1-based)
+     * @param channel (0-based)
      * @param noteNumber
      * @param velocity
      */
@@ -27,7 +27,7 @@ public:
     /**
      * @brief Register a note off and get the note duration
      *
-     * @param channel (1-based)
+     * @param channel (0-based)
      * @param noteNumber
      * @return float
      */
@@ -36,7 +36,7 @@ public:
     /**
      * @brief Get the note on velocity for a given note
      *
-     * @param channel (1-based)
+     * @param channel (0-based)
      * @param noteNumber
      * @return uint8_t
      */
diff --git a/src/sfizz/Region.cpp b/src/sfizz/Region.cpp
index 08d5be05..3ab0c267 100644
--- a/src/sfizz/Region.cpp
+++ b/src/sfizz/Region.cpp
@@ -134,10 +134,18 @@ bool sfz::Region::parseOpcode(const Opcode& opcode)
 
     // Region logic: MIDI conditions
     case hash("lochan"):
-        setRangeStartFromOpcode(opcode, channelRange, Default::channelRange);
+        {
+            const auto value = readOpcode(opcode.value, Default::channelRange);
+            if (value)
+                channelRange.setStart(*value - 1);
+        }
         break;
     case hash("hichan"):
-        setRangeEndFromOpcode(opcode, channelRange, Default::channelRange);
+        {
+            const auto value = readOpcode(opcode.value, Default::channelRange);
+            if (value)
+                channelRange.setEnd(*value - 1);
+        }
         break;
     case hash("lobend"):
         setRangeStartFromOpcode(opcode, bendRange, Default::bendRange);
diff --git a/src/sfizz/Region.h b/src/sfizz/Region.h
index 441acb09..9b1fa044 100644
--- a/src/sfizz/Region.h
+++ b/src/sfizz/Region.h
@@ -93,7 +93,7 @@ struct Region {
      * @brief Register a new note on event. The region may be switched on or off using keys so
      * this function updates the keyswitches state.
      *
-     * @param channel MIDI channel (1-based)
+     * @param channel MIDI channel (0-based)
      * @param noteNumber
      * @param velocity
      * @param randValue a random value between 0 and 1 used to randomize a bit the region activations
@@ -106,7 +106,7 @@ struct Region {
      * @brief Register a new note off event. The region may be switched on or off using keys so
      * this function updates the keyswitches state.
      *
-     * @param channel MIDI channel (1-based)
+     * @param channel MIDI channel (0-based)
      * @param noteNumber
      * @param velocity
      * @param randValue a random value between 0 and 1 used to randomize a bit the region activations
@@ -119,7 +119,7 @@ struct Region {
      * @brief Register a new CC event. The region may be switched on or off using CCs so
      * this function checks if it indeeds need to activate or not.
      *
-     * @param channel MIDI channel (1-based)
+     * @param channel MIDI channel (0-based)
      * @param ccNumber
      * @param ccValue
      * @return true if the region should trigger on this event
@@ -129,14 +129,14 @@ struct Region {
     /**
      * @brief Register a new pitch wheel event.
      *
-     * @param channel MIDI channel (1-based)
+     * @param channel MIDI channel (0-based)
      * @param pitch
      */
     void registerPitchWheel(int channel, int pitch) noexcept;
     /**
      * @brief Register a new aftertouch event.
      *
-     * @param channel MIDI channel (1-based)
+     * @param channel MIDI channel (0-based)
      * @param aftertouch
      */
     void registerAftertouch(int channel, uint8_t aftertouch) noexcept;
@@ -177,7 +177,7 @@ struct Region {
      * @brief Get the base volume of the region depending on which note has been
      * pressed to trigger the region.
      *
-     * @param channel (1-based)
+     * @param channel (0-based)
      * @param noteNumber
      * @return float
      */
@@ -247,7 +247,7 @@ struct Region {
     Range<uint8_t> velocityRange { Default::velocityRange }; // hivel and lovel
 
     // Region logic: MIDI conditions
-    Range<uint8_t> channelRange { Default::channelRange }; //lochan and hichan
+    Range<uint8_t> channelRange { Default::midiChannelRange }; //lochan and hichan
     Range<int> bendRange { Default::bendRange }; // hibend and lobend
     CCMap<Range<uint8_t>> ccConditions { Default::ccRange };
     Range<uint8_t> keyswitchRange { Default::keyRange }; // sw_hikey and sw_lokey
diff --git a/src/sfizz/SfzHelpers.h b/src/sfizz/SfzHelpers.h
index 96f3266f..ff0f15a0 100644
--- a/src/sfizz/SfzHelpers.h
+++ b/src/sfizz/SfzHelpers.h
@@ -35,28 +35,6 @@ using CCValueArray = std::array<uint8_t, 128>;
 using CCValuePair = std::pair<uint8_t, float> ;
 using CCNamePair = std::pair<uint8_t, std::string>;
 
-/**
- * @brief Translates the zero-based MIDI channel to the 1-based SFZ channel
- *
- * @param zeroBasedChannel
- * @return constexpr int
- */
-constexpr int translateMidiChannelToSfz(int zeroBasedChannel)
-{
-    return zeroBasedChannel + 1;
-}
-
-/**
- * @brief Translates the 1-based SFZ channel to the 0-based MIDI channel
- *
- * @param zeroBasedChannel
- * @return constexpr int
- */
-constexpr int translateSfzChannelToMidi(int oneBasedChannel)
-{
-    return oneBasedChannel - 1;
-}
-
 /**
  * @brief Converts cents to a pitch ratio
  *
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 81cdf979..5c01eda0 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -380,7 +380,6 @@ void sfz::Synth::noteOn(int delay, int channel, int noteNumber, uint8_t velocity
     ASSERT(noteNumber < 128);
     ASSERT(noteNumber >= 0);
 
-    channel = translateMidiChannelToSfz(channel);
     midiState.noteOnEvent(channel, noteNumber, velocity);
 
     AtomicGuard callbackGuard { inCallback };
@@ -410,7 +409,6 @@ void sfz::Synth::noteOff(int delay, int channel, int noteNumber, uint8_t velocit
     ASSERT(noteNumber < 128);
     ASSERT(noteNumber >= 0);
 
-    channel = translateMidiChannelToSfz(channel);
     AtomicGuard callbackGuard { inCallback };
     if (!canEnterCallback)
         return;
@@ -440,7 +438,6 @@ void sfz::Synth::cc(int delay, int channel, int ccNumber, uint8_t ccValue) noexc
     ASSERT(ccNumber < 128);
     ASSERT(ccNumber >= 0);
 
-    channel = translateMidiChannelToSfz(channel);
 
     AtomicGuard callbackGuard { inCallback };
     if (!canEnterCallback)
@@ -466,15 +463,14 @@ void sfz::Synth::pitchWheel(int delay, int channel, int pitch) noexcept
 {
     ASSERT(pitch <= 8192);
     ASSERT(pitch >= -8192);
-    channel = translateMidiChannelToSfz(channel);
+
     midiState.pitchBendEvent(channel, pitch);
     for (auto& voice: voices) {
         voice->registerPitchWheel(delay, channel, pitch);
     }
 }
-void sfz::Synth::aftertouch(int /* delay */, int channel, uint8_t /* aftertouch */) noexcept
+void sfz::Synth::aftertouch(int /* delay */, int /*channel*/, uint8_t /* aftertouch */) noexcept
 {
-    channel = translateMidiChannelToSfz(channel);
 }
 void sfz::Synth::tempo(int /* delay */, float /* secondsPerQuarter */) noexcept
 {
diff --git a/src/sfizz/Voice.h b/src/sfizz/Voice.h
index 619ab771..8b94abda 100644
--- a/src/sfizz/Voice.h
+++ b/src/sfizz/Voice.h
@@ -92,7 +92,7 @@ public:
      *
      * @param region
      * @param delay
-     * @param channel
+     * @param channel (0-based)
      * @param number
      * @param value
      * @param triggerType
@@ -103,7 +103,7 @@ public:
      * @brief Register a note-off event; this may trigger a release.
      *
      * @param delay
-     * @param channel
+     * @param channel (0-based)
      * @param noteNumber
      * @param velocity
      */
@@ -114,7 +114,7 @@ public:
      * parameter.
      *
      * @param delay
-     * @param channel
+     * @param channel (0-based)
      * @param ccNumber
      * @param ccValue
      */
@@ -123,7 +123,7 @@ public:
      * @brief Register a pitch wheel event; for now this does nothing
      *
      * @param delay
-     * @param channel
+     * @param channel (0-based)
      * @param pitch
      */
     void registerPitchWheel(int delay, int channel, int pitch) noexcept;
@@ -131,7 +131,7 @@ public:
      * @brief Register an aftertouch event; for now this does nothing
      *
      * @param delay
-     * @param channel
+     * @param channel (0-based)
      * @param aftertouch
      */
     void registerAftertouch(int delay, int channel, uint8_t aftertouch) noexcept;
@@ -139,7 +139,7 @@ public:
      * @brief Register a tempo event; for now this does nothing
      *
      * @param delay
-     * @param channel
+     * @param channel (0-based)
      * @param pitch
      */
     void registerTempo(int delay, float secondsPerQuarter) noexcept;
@@ -243,7 +243,7 @@ private:
     /**
      * @brief Computes the values for the envelope depending on the note or CC number and the velocity/cc value
      *
-     * @param channel
+     * @param channel (0-based)
      * @param delay
      * @param velocity
      */
diff --git a/tests/FilesT.cpp b/tests/FilesT.cpp
index 3436401d..563fa38f 100644
--- a/tests/FilesT.cpp
+++ b/tests/FilesT.cpp
@@ -50,7 +50,7 @@ TEST_CASE("[Files] Basic opcodes (regions_opcodes.sfz)")
     sfz::Synth synth;
     synth.loadSfzFile(fs::current_path() / "tests/TestFiles/Regions/regions_opcodes.sfz");
     REQUIRE(synth.getNumRegions() == 1);
-    REQUIRE(synth.getRegionView(0)->channelRange == sfz::Range<uint8_t>(2, 14));
+    REQUIRE(synth.getRegionView(0)->channelRange == sfz::Range<uint8_t>(1, 13));
 }
 
 TEST_CASE("[Files] Underscore opcodes (underscore_opcodes.sfz)")
diff --git a/tests/MidiStateT.cpp b/tests/MidiStateT.cpp
index da49b71d..0498a884 100644
--- a/tests/MidiStateT.cpp
+++ b/tests/MidiStateT.cpp
@@ -39,20 +39,20 @@ TEST_CASE("[MidiState] Initial values")
         REQUIRE( cc == 0 );
     for (auto& cc: state.getCCArray(6))
         REQUIRE( cc == 0 );
-    for (int channel = 1; channel <= 16; ++channel)
+    for (int channel = 0; channel < 16; ++channel)
         REQUIRE( state.getPitchBend(channel) == 0 );
 }
 
 TEST_CASE("[MidiState] Set and get CCs")
 {
     sfz::MidiState state;
-    const auto& cc1 = state.getCCArray(1);
+    const auto& cc0 = state.getCCArray(0);
     const auto& cc6 = state.getCCArray(6);
     const auto& cc12 = state.getCCArray(12);
-    state.ccEvent(1, 24, 23);
+    state.ccEvent(0, 24, 23);
     state.ccEvent(6, 123, 124);
-    REQUIRE(state.getCCValue(1, 24) == 23);
-    REQUIRE(cc1[24] == 23);
+    REQUIRE(state.getCCValue(0, 24) == 23);
+    REQUIRE(cc0[24] == 23);
     REQUIRE(state.getCCValue(6, 123) == 124);
     REQUIRE(cc6[123] == 124);
     REQUIRE(+state.getCCValue(12, 24) == 0);
@@ -64,33 +64,33 @@ TEST_CASE("[MidiState] Set and get CCs")
 TEST_CASE("[MidiState] Set and get pitch bends")
 {
     sfz::MidiState state;
-    state.pitchBendEvent(1, 894);
-    REQUIRE(state.getPitchBend(1) == 894);
+    state.pitchBendEvent(0, 894);
+    REQUIRE(state.getPitchBend(0) == 894);
     REQUIRE(state.getPitchBend(6) == 0);
-    state.pitchBendEvent(1, 0);
-    REQUIRE(state.getPitchBend(1) == 0);
+    state.pitchBendEvent(0, 0);
+    REQUIRE(state.getPitchBend(0) == 0);
     REQUIRE(state.getPitchBend(6) == 0);
 }
 
 TEST_CASE("[MidiState] Reset")
 {
     sfz::MidiState state;
-    state.pitchBendEvent(1, 894);
+    state.pitchBendEvent(0, 894);
     state.noteOnEvent(6, 64, 24);
-    state.ccEvent(16, 123, 124);
+    state.ccEvent(15, 123, 124);
     state.reset();
-    REQUIRE(state.getPitchBend(1) == 0);
+    REQUIRE(state.getPitchBend(0) == 0);
     REQUIRE(state.getNoteVelocity(6, 64) == 0);
-    REQUIRE(state.getCCValue(16, 123) == 0);
+    REQUIRE(state.getCCValue(15, 123) == 0);
 }
 
 TEST_CASE("[MidiState] Set and get note velocities")
 {
     sfz::MidiState state;
-    state.noteOnEvent(1, 64, 24);
-    REQUIRE(+state.getNoteVelocity(1, 64) == 24);
-    REQUIRE(+state.getNoteVelocity(2, 64) == 0);
-    state.noteOnEvent(1, 64, 123);
-    REQUIRE(+state.getNoteVelocity(1, 64) == 123);
-    REQUIRE(+state.getNoteVelocity(16, 64) == 0);
+    state.noteOnEvent(0, 64, 24);
+    REQUIRE(+state.getNoteVelocity(0, 64) == 24);
+    REQUIRE(+state.getNoteVelocity(1, 64) == 0);
+    state.noteOnEvent(0, 64, 123);
+    REQUIRE(+state.getNoteVelocity(0, 64) == 123);
+    REQUIRE(+state.getNoteVelocity(15, 64) == 0);
 }
\ No newline at end of file
diff --git a/tests/RegionT.cpp b/tests/RegionT.cpp
index 62581863..c4fd94a8 100644
--- a/tests/RegionT.cpp
+++ b/tests/RegionT.cpp
@@ -238,19 +238,19 @@ TEST_CASE("[Region] Parsing opcodes")
 
     SECTION("lochan, hichan")
     {
-        REQUIRE(region.channelRange == sfz::Range<uint8_t>(1, 16));
+        REQUIRE(region.channelRange == sfz::Range<uint8_t>(0, 15));
         region.parseOpcode({ "lochan", "4" });
-        REQUIRE(region.channelRange == sfz::Range<uint8_t>(4, 16));
+        REQUIRE(region.channelRange == sfz::Range<uint8_t>(3, 15));
         region.parseOpcode({ "lochan", "128" });
-        REQUIRE(region.channelRange == sfz::Range<uint8_t>(16, 16));
+        REQUIRE(region.channelRange == sfz::Range<uint8_t>(15, 15));
         region.parseOpcode({ "lochan", "-3" });
-        REQUIRE(region.channelRange == sfz::Range<uint8_t>(1, 16));
+        REQUIRE(region.channelRange == sfz::Range<uint8_t>(0, 15));
         region.parseOpcode({ "hichan", "13" });
-        REQUIRE(region.channelRange == sfz::Range<uint8_t>(1, 13));
+        REQUIRE(region.channelRange == sfz::Range<uint8_t>(0, 12));
         region.parseOpcode({ "hichan", "-1" });
-        REQUIRE(region.channelRange == sfz::Range<uint8_t>(1, 1));
+        REQUIRE(region.channelRange == sfz::Range<uint8_t>(0, 0));
         region.parseOpcode({ "hichan", "128" });
-        REQUIRE(region.channelRange == sfz::Range<uint8_t>(1, 16));
+        REQUIRE(region.channelRange == sfz::Range<uint8_t>(0, 15));
     }
 
     SECTION("lobend, hibend")
diff --git a/tests/RegionTriggersT.cpp b/tests/RegionTriggersT.cpp
index 21d773f6..a224257b 100644
--- a/tests/RegionTriggersT.cpp
+++ b/tests/RegionTriggersT.cpp
@@ -34,44 +34,44 @@ TEST_CASE("Basic triggers", "Region triggers")
     SECTION("key")
     {
         region.parseOpcode({ "key", "40" });
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.5f));
-        REQUIRE(!region.registerNoteOff(1, 40, 64, 0.5f));
-        REQUIRE(!region.registerNoteOn(1, 41, 64, 0.5f));
-        REQUIRE(!region.registerCC(1, 63, 64));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOff(0, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 41, 64, 0.5f));
+        REQUIRE(!region.registerCC(0, 63, 64));
     }
     SECTION("lokey and hikey")
     {
         region.parseOpcode({ "lokey", "40" });
         region.parseOpcode({ "hikey", "42" });
-        REQUIRE(!region.registerNoteOn(1, 39, 64, 0.5f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.5f));
-        REQUIRE(!region.registerNoteOff(1, 40, 64, 0.5f));
-        REQUIRE(region.registerNoteOn(1, 41, 64, 0.5f));
-        REQUIRE(region.registerNoteOn(1, 42, 64, 0.5f));
-        REQUIRE(!region.registerNoteOn(1, 43, 64, 0.5f));
-        REQUIRE(!region.registerNoteOff(1, 42, 64, 0.5f));
-        REQUIRE(!region.registerNoteOff(1, 42, 64, 0.5f));
-        REQUIRE(!region.registerCC(1, 63, 64));
+        REQUIRE(!region.registerNoteOn(0, 39, 64, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOff(0, 40, 64, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 41, 64, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 42, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 43, 64, 0.5f));
+        REQUIRE(!region.registerNoteOff(0, 42, 64, 0.5f));
+        REQUIRE(!region.registerNoteOff(0, 42, 64, 0.5f));
+        REQUIRE(!region.registerCC(0, 63, 64));
     }
     SECTION("key and release trigger")
     {
         region.parseOpcode({ "key", "40" });
         region.parseOpcode({ "trigger", "release" });
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.5f));
-        REQUIRE(region.registerNoteOff(1, 40, 64, 0.5f));
-        REQUIRE(!region.registerNoteOn(1, 41, 64, 0.5f));
-        REQUIRE(!region.registerNoteOff(1, 41, 64, 0.5f));
-        REQUIRE(!region.registerCC(1, 63, 64));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(region.registerNoteOff(0, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 41, 64, 0.5f));
+        REQUIRE(!region.registerNoteOff(0, 41, 64, 0.5f));
+        REQUIRE(!region.registerCC(0, 63, 64));
     }
     SECTION("key and release_key trigger")
     {
         region.parseOpcode({ "key", "40" });
         region.parseOpcode({ "trigger", "release_key" });
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.5f));
-        REQUIRE(region.registerNoteOff(1, 40, 64, 0.5f));
-        REQUIRE(!region.registerNoteOn(1, 41, 64, 0.5f));
-        REQUIRE(!region.registerNoteOff(1, 41, 64, 0.5f));
-        REQUIRE(!region.registerCC(1, 63, 64));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(region.registerNoteOff(0, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 41, 64, 0.5f));
+        REQUIRE(!region.registerNoteOff(0, 41, 64, 0.5f));
+        REQUIRE(!region.registerCC(0, 63, 64));
     }
     // TODO: first and legato triggers
     SECTION("lovel and hivel")
@@ -79,22 +79,22 @@ TEST_CASE("Basic triggers", "Region triggers")
         region.parseOpcode({ "key", "40" });
         region.parseOpcode({ "lovel", "60" });
         region.parseOpcode({ "hivel", "70" });
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.5f));
-        REQUIRE(region.registerNoteOn(1, 40, 60, 0.5f));
-        REQUIRE(region.registerNoteOn(1, 40, 70, 0.5f));
-        REQUIRE(!region.registerNoteOn(1, 41, 71, 0.5f));
-        REQUIRE(!region.registerNoteOn(1, 41, 59, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 40, 60, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 40, 70, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 41, 71, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 41, 59, 0.5f));
     }
     SECTION("lochan and hichan")
     {
         region.parseOpcode({ "key", "40" });
         region.parseOpcode({ "lochan", "2" });
         region.parseOpcode({ "hichan", "4" });
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(region.registerNoteOn(1, 40, 64, 0.5f));
         REQUIRE(region.registerNoteOn(2, 40, 64, 0.5f));
         REQUIRE(region.registerNoteOn(3, 40, 64, 0.5f));
-        REQUIRE(region.registerNoteOn(4, 40, 64, 0.5f));
-        REQUIRE(!region.registerNoteOn(5, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(4, 40, 64, 0.5f));
     }
 
     SECTION("lorand and hirand")
@@ -102,37 +102,37 @@ TEST_CASE("Basic triggers", "Region triggers")
         region.parseOpcode({ "key", "40" });
         region.parseOpcode({ "lorand", "0.35" });
         region.parseOpcode({ "hirand", "0.40" });
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.34f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.35f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.36f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.37f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.38f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.39f));
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.40f));
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.41f));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.34f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.35f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.36f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.37f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.38f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.39f));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.40f));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.41f));
     }
 
     SECTION("lorand and hirand on 1.0f")
     {
         region.parseOpcode({ "key", "40" });
         region.parseOpcode({ "lorand", "0.35" });
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.34f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.35f));
-        REQUIRE(region.registerNoteOn(1, 40, 64, 1.0f));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.34f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.35f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 1.0f));
     }
 
     SECTION("on_loccN, on_hiccN")
     {
         region.parseOpcode({ "on_locc47", "64" });
         region.parseOpcode({ "on_hicc47", "68" });
-        REQUIRE(!region.registerCC(1, 47, 63));
-        REQUIRE(region.registerCC(1, 47, 64));
-        REQUIRE(region.registerCC(1, 47, 65));
-        REQUIRE(region.registerCC(1, 47, 66));
-        REQUIRE(region.registerCC(1, 47, 67));
-        REQUIRE(region.registerCC(1, 47, 68));
-        REQUIRE(!region.registerCC(1, 47, 69));
-        REQUIRE(!region.registerCC(1, 40, 64));
+        REQUIRE(!region.registerCC(0, 47, 63));
+        REQUIRE(region.registerCC(0, 47, 64));
+        REQUIRE(region.registerCC(0, 47, 65));
+        REQUIRE(region.registerCC(0, 47, 66));
+        REQUIRE(region.registerCC(0, 47, 67));
+        REQUIRE(region.registerCC(0, 47, 68));
+        REQUIRE(!region.registerCC(0, 47, 69));
+        REQUIRE(!region.registerCC(0, 40, 64));
     }
 }
 
@@ -146,11 +146,11 @@ TEST_CASE("Legato triggers", "Region triggers")
         region.parseOpcode({ "lokey", "40" });
         region.parseOpcode({ "hikey", "50" });
         region.parseOpcode({ "trigger", "first" });
-        REQUIRE(region.registerNoteOn(1, 40, 64, 0.5f));
-        REQUIRE(!region.registerNoteOn(1, 41, 64, 0.5f));
-        region.registerNoteOff(1, 40, 0, 0.5f);
-        region.registerNoteOff(1, 41, 0, 0.5f);
-        REQUIRE(region.registerNoteOn(1, 42, 64, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 41, 64, 0.5f));
+        region.registerNoteOff(0, 40, 0, 0.5f);
+        region.registerNoteOff(0, 41, 0, 0.5f);
+        REQUIRE(region.registerNoteOn(0, 42, 64, 0.5f));
     }
 
     SECTION("Second note playing")
@@ -158,10 +158,10 @@ TEST_CASE("Legato triggers", "Region triggers")
         region.parseOpcode({ "lokey", "40" });
         region.parseOpcode({ "hikey", "50" });
         region.parseOpcode({ "trigger", "legato" });
-        REQUIRE(!region.registerNoteOn(1, 40, 64, 0.5f));
-        REQUIRE(region.registerNoteOn(1, 41, 64, 0.5f));
-        region.registerNoteOff(1, 40, 0, 0.5f);
-        region.registerNoteOff(1, 41, 0, 0.5f);
-        REQUIRE(!region.registerNoteOn(1, 42, 64, 0.5f));
+        REQUIRE(!region.registerNoteOn(0, 40, 64, 0.5f));
+        REQUIRE(region.registerNoteOn(0, 41, 64, 0.5f));
+        region.registerNoteOff(0, 40, 0, 0.5f);
+        region.registerNoteOff(0, 41, 0, 0.5f);
+        REQUIRE(!region.registerNoteOn(0, 42, 64, 0.5f));
     }
 }
\ No newline at end of file