Sequences

Named lists of PLAY and REST events. Durations are in beats (relative to BPM). Events play one after another (sequentially).

SEQUENCE melody:
    PLAY lead C4 0.5      # play instrument "lead", note C4, half a beat
    PLAY lead D#4 0.5     # sharps with #
    PLAY lead E4 1        # one beat
    REST 0.5              # silence for half a beat
    PLAY lead G4 2        # two beats

PLAY Syntax

PLAY <instrument> <note> <duration> [velocity] [CUTOFF:<value>] [REVERB:<value>] [DELAY:<time>:<feedback>]
PLAY <instrument> [C4 E4 G4] <duration> [velocity] [CUTOFF:<value>] [REVERB:<value>] [DELAY:<time>:<feedback>]

• instrument — must match a defined INSTRUMENT name
• note — scientific pitch notation (e.g. C4, D#3, Bb2)
• chord — bracket notation [note note note] for polyphonic playback (min 2 notes)
• duration — float, in beats relative to BPM (e.g. 0.25 = sixteenth note at 4/4)
• velocity — optional, 0–255. Per-note volume scaling. Omit for full instrument volume
• CUTOFF:value — optional per-note filter override (20–20000 Hz). Instrument must have CUTOFF set. Reverts after note ends
• REVERB:value — optional per-note reverb override (0–255)
• DELAY:time:feedback — optional per-note delay override (time 0–2000ms, feedback 0–255)

For drums without a melodic pitch, omit the note:

PLAY kick 1             # drum hit, 1 beat duration

note

Drum instruments ignore the note parameter entirely — their pitch is set by the FREQ property in the instrument definition.

REST Syntax

REST <duration>

Silent pause for the given number of beats.

Per-note Effect Overrides

Override an instrument's settings for individual notes:

SEQUENCE melody:
    PLAY lead C4 1 200 CUTOFF:800          # darker filter on this note
    PLAY lead E4 1                          # normal instrument settings
    PLAY lead G4 1 180 DELAY:500:120       # longer delay on this note
    PLAY lead C5 1 200 REVERB:180 DELAY:400:100   # multiple overrides
    PLAY lead D5 1 180 CUTOFF:3000 REVERB:200      # bright + wet

Overrides require velocity to be specified first. CUTOFF override only works on instruments that have CUTOFF set — the filter reverts to the instrument's base value after the note ends.

VELOCITY_CURVE

Automatically spread velocities across a series of notes — creates crescendo or decrescendo without writing each velocity by hand.

VELOCITY_CURVE CRESCENDO <start_vel> <end_vel> <note_count>
VELOCITY_CURVE DECRESCENDO <start_vel> <end_vel> <note_count>
VELOCITY_CURVE OFF

Parameter	Range	Description
start_vel	0–255	Starting velocity
end_vel	0–255	Ending velocity
note_count	1–128	How many subsequent PLAY notes the curve spans

Crescendo Example

SEQUENCE buildup:
    VELOCITY_CURVE CRESCENDO 40 230 6
    PLAY lead C4 0.5       # vel ~40
    PLAY lead D4 0.5       # vel ~78
    PLAY lead E4 0.5       # vel ~116
    PLAY lead F4 0.5       # vel ~154
    PLAY lead G4 0.5       # vel ~192
    PLAY lead A4 1         # vel ~230

Decrescendo Example

SEQUENCE fadeout:
    VELOCITY_CURVE DECRESCENDO 200 60 4
    PLAY lead G4 1         # vel ~200
    PLAY lead E4 1         # vel ~153
    PLAY lead C4 1         # vel ~107
    PLAY lead C3 2         # vel ~60

Notes

• VELOCITY_CURVE is compile-time only — zero MCU runtime cost. Velocities are baked into the event table
• A note with an explicit velocity override still uses it, but the curve position advances
• VELOCITY_CURVE OFF cancels an active curve before it finishes
• REST events do not consume curve positions
• Multiple VELOCITY_CURVEs in the same sequence: each replaces the previous

tip

VELOCITY_CURVE is resolved at compile time — it adds zero overhead on the microcontroller. Use it freely for musical expression.

Chords

Play multiple notes simultaneously with bracket notation:

SEQUENCE progression:
    PLAY pad [C4 E4 G4] 2       # C major chord, 2 beats
    PLAY pad [A3 C4 E4] 2       # A minor chord
    PLAY pad [F3 A3 C4] 2       # F major chord
    PLAY pad [G3 B3 D4] 2       # G major chord