OpenMPT manual — Instruments

The instrument tab of openmpt: multisampling and the sample map, volume/pan/pitch-filter envelopes, New Note Actions, the resonant filter defaults, random variation, pitch/pan separation and plugin routing — the IT instrument model as the modern tracker exposes it.

Key claims#

• An instrument is "an additional layer above samples" holding one or several samples assigned to keys (multisampling — a piano sample per note, or a GM-style drum set) plus volume, panning and pitch/filter envelopes; IT and MPTM files start in sample mode, "New Instrument" converts every sample to an instrument.
• Global Volume (64 = no attenuation), Fade Out (fade lasts 32768 ÷ value ticks after the envelope ends, a note-fade command or NNA Note Fade), Pan (overrides channel pan, overridden by commands and sample pan). Pitch / Pan Separation spreads notes across the stereo field around a centre note; negative values invert it.
• Filter: per-instrument resonance, cutoff and (MPTM) filter mode; without defaults the previous note's filter values on that channel are reused — set resonance to minimum and cutoff to maximum to disable. Random Variation: volume swing, pan swing, and (MPTM) cutoff and resonance swing.
• New Note Actions: Note Cut (default), Continue ("mostly useful with short one-shot samples such as percussion"; looped samples continue "indefinitely until you trigger one of the 'Past Note' effects S70, S71 or S72"), Note Off (releases sustain loops), Note Fade (with Fade Out 0 it equals Continue). Duplicate Note Check by note, sample, instrument or plugin, with its own action.
• Sample Map: pattern note → heard note + sample; for drum kits "simply map all notes to C-5"; XM lacks the note column and allows only 16 samples per instrument. Context menu: transpose the map, reset it, "Transpose Samples / Reset Map" for saner IT portamento with SFZ imports.
• Envelopes: volume 0–100 %, panning ±32 relative to the current pan, pitch in quarter-tone steps (±16 semitones) or acting as a filter cutoff envelope; the time unit is the tick ("increasing the song tempo increases the envelope speed", pitch does not). Loop, sustain loop (exited on Note Off; XM uses whichever comes first, IT considers sustain first) and Envelope Carry (do not restart on a new note; pick an NNA other than Note Cut, as some IT drivers ignore carry otherwise); a release node resumes the envelope on Note Off with following nodes relative to the release volume. Nodes: Shift-click / double-click to add, Ctrl-drag to move the tail; Scale Envelope Points stretches or amplifies.
• Plugin section: MIDI channel ("Mapped" = pattern channel mod 16), program and bank, pitch bend range so portamento and vibrato work on plugins, volume-command handling (none / MIDI volume / dry-wet), velocities.

Practical takeaways#

Drum kits = one instrument, all notes mapped to C-5; percussion with NNA Continue and a fade; chip leads with a pitch envelope in quarter tones; and remember that envelopes run in ticks, so they speed up with the tempo.

Notable quotes#

"New Note Actions are a great way to save pattern channels that would otherwise be used just fading out playing notes."

Pages touched#

openmpt · instrument-envelopes · new-note-actions · multisampling · filter-programming · randomization-and-probability · stereo-panning · impulse-tracker