FluidFeatures

This is a list of MIDI events that fluidsynth handles by default. That "handling" is either given by

• the SoundFont spec, or
• the General MIDI standard.

While the explanations in the SoundFont spec are very precise in terms of the intended audio-synthetic articulation, the descriptions in the MIDI standard are very vague when it comes to sound articulation. Thus you cannot expect that fluidsynth behaves in a certain way (which you may know from other synths) just because you send some MIDI CCs.

In order to control those "underspecifed" aspects of the sound synthesis (like ADSR, low pass filter cutoff & resonance, tremolo & vibrato depth, etc.) custom SoundFont modulators must be used! The SoundFont spec wants the SoundFont designer to define those modulators in the SoundFont file itself. Doing so will give you great portability between any SF2 compliant synth, i.e. you would get the same sound articulation when sending your custom CCs to any SF2 compliant synth to trigger your custom effects. Unfortunately, defining those modulators must be done for every single instrument or preset in the SoundFont, which can be tiresome and error-prone. Alternatively, you can use fluidsynth's API for manipulating default modulators (see fluid_synth_add_default_mod() and fluid_synth_remove_default_mod() resp.). This will allow you to insert or remove your own custom modulators, which will then affect all loaded SoundFonts equally. However, this technique is not portable and limited to fluidsynth.

Legend

✔️ Implemented according to MIDI or SoundFont spec and usable by default

✅ Partially or customly implemented and usable by default

⚠️ Attention, this may require special setup of fluidsynth to be usable by default

❌ Not handled by default, but usable via custom SoundFont modulators

MIDI Message Implementation Chart

MIDI Message	Implementation Status
NOTE_OFF	✔️
NOTE_ON	✔️
CONTROL_CHANGE	✅ See related table below.
MIDI_SET_TEMPO	✔️
PROGRAM_CHANGE	✔️
CHANNEL_PRESSURE	✔️ SF2 default modulator
KEY_PRESSURE	❌
PITCH_BEND	✔️ SF2 default modulator
MIDI_SYSTEM_RESET	✔️

MIDI Control Change Implementation Chart

Note that unless otherwise documented, CCs are interpreted individually, i.e. as 7-bit values.

MIDI CC	Implementation Status
(000) Bank Select	✔️ Interpretation of MSB and LSB depends on synth.midi-bank-select
(001) Modulation Wheel	✔️ SF2 default modulator
(002) Breath Controller	⚠️ Usable in breathmode, see PolyMono documentation
(004) Foot Controller	❌
(005) Portamento Time	✔️ MSB and LSB (i.e. 14-bit value!), see PolyMono documentation
(006) Data Entry	✔️ MSB and LSB (i.e. 14-bit value!).
(007) Channel Volume	✔️ SF2 default modulator
(008) Balance	✅ non-standard default SF2 modulator
(010) Pan	✔️ SF2 default modulator
(011) Expression	✔️ SF2 default modulator
(064) Sustain Pedal	✔️ See Sostenuto documentation
(065) Portamento Switch	✔️ See PolyMono documentation
(066) Sostenuto Pedal	✔️ See Sostenuto documentation
(068) Legato Switch	✔️ See PolyMono documentation
(072) Sound Controller 3 (default: Release Time)	❌
(073) Sound Controller 4 (default: Attack Time)	❌
(074) Sound Controller 5 (default: Brightness)	❌
(084) Portamento Control (PTC)	✔️ See PolyMono documentation
(091) Effects 1 Depth (Reverb Send Level)	✔️ SF2 default modulator
(092) Effects 2 Depth (Tremolo Depth)	❌
(093) Effects 3 Depth (Chorus Send Level)	✔️ SF2 default modulator
(094) Effects 4 Depth (Celeste (Detune) Depth)	❌
(095) Effects 5 Depth (Phaser Depth)	❌
(098) NRPN LSB	✔️ See related table below
(099) NRPN MSB	✔️ See related table below
(100) RPN LSB	✅ See related table below
(101) RPN MSB	✅ See related table below
(120) All Sound Off	✔️
(121) Reset All Controllers	✔️
(121) Local Control	✔️ Ignored, because not applicable
(123) All Notes Off	✔️
(124) Omni Mode Off	✔️ See PolyMono documentation
(125) Omni Mode On	✔️ See PolyMono documentation
(126) Mono Mode	✔️ See PolyMono documentation
(127) Poly Mode	✔️ See PolyMono documentation

RPN Control Change Implementation Chart

RPN CC	Implementation Status
(000) RPN_PITCH_BEND_RANGE	✔️ SF2 default modulator
(001) RPN_CHANNEL_FINE_TUNE	✔️
(002) RPN_CHANNEL_COARSE_TUNE	✔️
(003) Tuning Program Select	✔️
(004) Tuning Bank Select	✔️
(005) Modulation Depth Range	❌ Not yet implemented
(006) MPE Configuration Message	❌ Not yet implemented

NRPN Control Change Implementation Chart

SF2 NRPNs

✔️ All SF2 generators can be altered with NRPN Control Change messages. See section 8.1.2 in the spec.

AWE32 NRPNs

As of version 2.4.5, fluidsynth also supports NPRN control found in the AWE32. Most of it is implemented according to the "AWE32 Developer's Information Pack", which however was found to be quite buggy, so fluidsynth's behavior may differ from that of real SoundBlaster card. Unless otherwise noted, the data value received by any of these NRPNs overrides the initial generator value of the corresponding SF2 generator.

NRPN MSB	NRPN LSB	Implementation Status
127	0	✅ overrides Modulation LFO delay generator
127	1	✅ overrides Modulation LFO frequency generator
127	2	✅ overrides Vibrato LFO delay generator
127	3	✅ overrides Vibrato LFO frequency generator
127	4	✅ overrides Modulation envelope delay generator
127	5	✅ overrides Modulation envelope attack generator
127	6	✅ overrides Modulation envelope hold generator
127	7	✅ overrides Modulation envelope decay generator
127	8	✅ overrides Modulation envelope sustain generator
127	9	✅ overrides Modulation envelope release generator
127	10	✅ overrides Volume envelope delay generator
127	11	✅ overrides Volume envelope attack generator
127	12	✅ overrides Volume envelope hold generator
127	13	✅ overrides Volume envelope decay generator
127	14	✅ overrides Volume envelope sustain generator
127	15	✅ overrides Volume envelope release generator
127	16	⚠️ treated as if a regular MIDI Pitch Wheel event is received
127	17	✅ overrides Modulation LFO to pitch generator
127	18	✅ overrides Vibrato LFO to pitch generator
127	19	✅ overrides Modulation envelope to pitch generator
127	20	✅ overrides Modulation LFO to volume generator
127	21	✔️ overrides Filter cutoff generator, ranges verified through listening tests (AWE32 documentation is incorrect)
127	22	✔️ overrides Filter Q generator, ranges verified through listening tests (AWE32 documentation is incorrect)
127	23	✅ overrides Modulation LFO to filter cutoff generator
127	24	✅ overrides Modulation envelope to filter cutoff generator
127	25	⚠️ received data value is transformed by default SF2 chorus modulator before applied to chorus generator
127	26	⚠️ received data value is transformed by default SF2 reverb modulator before applied to reverb generator

Roland NRPNs

Additionally, as of version 2.5.0, fluidsynth maps the following Roland NRPNs to regular CCs, allowing them to be overridden in a Soundfont by using modulators. The mapping was implemented according to the SC8850 owner's manual pages 227 and 228.

NRPN MSB	NRPN LSB	Implementation Status
0x01	0x08	✅ mapped to CC 76 (vibrato rate)
0x01	0x09	✅ mapped to CC 77 (vibrato depth)
0x01	0x0A	✅ mapped to CC 78 (vibrato delay)

SysEx Messages

Note: fluidsynth only processes those SysEx messages, if the "device-id" in the SysEx message matches the synth.device-id setting the synth has been initialized with! Broadcast SysEx messages are always processed.

SysEx	Implementation Status
MIDI Tuning Standard	✔️ See enum midi_sysex_tuning_msg_id for supported messages
GS DT1	✅ Only rhythm / melodic part selection messages are supported (since fluidsynth 2.2.0, see the "Patch Part parameters section in SC-88Pro/8850 owner's manual")
GM/GM2 mode on	✔️
GS reset	✔️
XG reset	✔️