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Effects

In this section we will finish Tutorial Groove by adding musical effects such as vibrato, arpeggio, and portamento, first inline on notes, then as reusable named presets.

Note: that effects available can vary by chip — see Sound Chip Plugins.

Using effects​

Attach an effect to a note with angle brackets after the pitch. The effect name and parameters use a colon to separate them. If the note has a length this should come after the effect angled brackets. An example of using effects is as follows:

pat lead_c = G5 . A5 C6<vib:6,4>:2 A5 G5 E5 .
pat bass_b = C3 . E3<port:16> . G2 . . G2
EffectExampleWhat it does
vibC6<vib:6,4>Vibrato — rate and depth
arpC4<arp:4,7>Arpeggio — semitone steps above the root
portE3<port:16>Portamento — slide into this note from the previous pitch

The arpeggio steps are offsets from the note itself, and the root is always played first — so you do not include 0. For example, C4<arp:4,7> rapidly cycles three pitches:

  • C4 — the root (0 semitones)
  • E4 — root + 4 semitones
  • G4 — root + 7 semitones

Together those offsets (4, 7) outline a C major chord. Change the offsets to change the chord — e.g. arp:3,7 gives C minor (C4, Eb4, G4).

Writing effects this way is fine for one-off use. When you reuse the same settings in several places, name them instead.

Named effect presets​

Define a reusable preset with effect <name> = <effect>. The right-hand side is the same effect body you would write inline, for example:

effect wobble = vib:6,4
effect spark  = arp:4,7
effect slide  = port:16

Give presets clear names so patterns stay readable, for example wobble, is easier to read than raw vib:6,4 everywhere.

Inline use of named presets​

Once defined, apply a preset on a note the same way as a built-in effect by putting the preset name in the brackets:

pat lead_c    = G5 . A5 C6<wobble>:2 A5 G5 E5 .
pat harmony_a = C4<spark>:4 E4:4 G4<spark>:4 E4:4
pat bass_b    = C3 . E3<slide> . G2 . . G2

Note: you can also attach a named preset as a sequence modifier so every note in a phrase gets it: seq lead = melody:wobble.

Tutorial Groove — finished​

Tutorial Groove now uses the three presets above: vibrato on the lead’s high note, arpeggios on the pulse2 harmony, and portamento on the wave bass. Press Play for the complete song:

Tutorial Groove — effects

Interactive playback loads in the browser.

…
effect wobble = vib:6,4
effect spark  = arp:4,7
effect slide  = port:16

pat lead_a = E5 . G5 C6 . G5 E5 . D5 . F5 A5 . G5 . .
pat lead_b = C5 . E5 G5 . E5 C5 . A4 . C5 E5 . D5 C5 .
pat lead_c = G5 . A5 C6<wobble>:2 A5 G5 E5 . F5 G5 A5 G5 E5 D5 C5

pat harmony_a = C4<spark>:4 E4:4 G4<spark>:4 E4:4
pat harmony_b = A3<spark>:4 C4:4 F4<spark>:4 G4:4

pat bass_a = C3 . . C3 G2 . . G2 A2 . . A2 F2 . G2 .
pat bass_b = C3 . E3<slide> . G2 . . G2 A2 . C3 . F2 . G2 .

pat drums_a = kick . hat . snare . hat hat kick . hat . snare hat hat .
pat drums_b = kick . hat hat snare . hat . kick kick hat . snare . snare .

seq lead_seq    = lead_a lead_b lead_a lead_c
seq harmony_seq = harmony_a harmony_b harmony_a harmony_b
seq bass_seq    = bass_a bass_b bass_a bass_b
seq drums_seq   = drums_a drums_b drums_a drums_b
…

Our Tutorial Groove song is now complete — feel free to Copy it into a .bax file and experiment further. Some ideas:

  • Change bpm 140 to something slower or faster and hear how the drums and lead sit
  • Swap duty cycles on the pulse instruments (12.5, 25, 50, 75) or try a different wave table for the bass
  • Add another lead phrase (lead_d) and extend lead_seq, or reorder A/B patterns so the form feels less regular
  • Tweak effect presets — deepen vibrato (vib:8,6), try a minor arpeggio (arp:3,7), or slow the portamento (port:8)
  • Apply a modifier from the previous section, e.g. lead_b:oct(+1) or drums_b:rev, on one occurrence in a sequence
  • Pan a phrase or add another effect from the Effects reference (tremolo, note cut, …)

Other sound chips​

The notes, patterns, sequences, and most effects in Tutorial Groove are chip-agnostic — the same musical material can target another backend by changing chip and rewriting the instruments (and channel map) for that hardware.

For example, on the NES you might keep lead_a / bass_seq as-is but define type=pulse1, type=triangle, and type=noise voices with NES fields instead of Game Boy duty / wave= / uge_note. Channel counts differ too (NES has five voices including DMC; SMS has three tones plus noise). Start from the Game Boy song, then follow the guide for your target chip under Sound Chip Plugins.

More effects​

Deep reference for panning, tremolo, note cut, retrigger, echo, volume slide, and export behaviour: Effects reference.

See also​