Instruments
AI Jam Sessions ships six sound engines plus a layered combinator that runs any two simultaneously.
Piano engines
Section titled “Piano engines”Oscillator Piano
Section titled “Oscillator Piano”Additive synthesis with multi-harmonic tone generation, hammer noise simulation, inharmonicity modeling, 48-voice polyphony, and stereo imaging. Zero external dependencies.
Six tunable keyboard voices, each adjustable per-parameter (brightness, decay, hammer hardness, detune, stereo width):
| Voice | Character |
|---|---|
| Concert Grand | Rich, full, classical |
| Upright | Warm, intimate, folk |
| Electric Piano | Silky, jazzy, Fender Rhodes feel |
| Honky-Tonk | Detuned, ragtime, saloon |
| Music Box | Crystalline, ethereal |
| Bright Grand | Cutting, contemporary, pop |
Sample Piano
Section titled “Sample Piano”Salamander Grand Piano — real recorded samples for the most authentic sound. The default engine whenever a pack is installed: put the full Salamander download at samples/AccurateSalamander (or point AI_JAM_SAMPLES_DIR at it) and play_song and the CLI pick it automatically; pass --engine piano to force the oscillator. The npm package itself stays sample-free.
The browser cockpit needs no setup at all — it ships its own pruned 8 MB pack (90 OGGs, three velocity layers) that loads on your first interaction. Samples by Alexander Holm, CC-BY 3.0.
Vocal engines
Section titled “Vocal engines”Looking for a sung line on the piano’s clock — real lyrics, real pitches, gated on timing and pitch? That is the Vocals route (a local score-conditioned singer), not one of the live engines below.
Vocal (Sample)
Section titled “Vocal (Sample)”Pitch-shifted sustained vowel tones with portamento and legato mode. Good for melodic lines where natural vocal timbre matters.
Vocal Tract
Section titled “Vocal Tract”Physical model based on the Pink Trombone architecture. Uses an LF glottal waveform through a 44-cell digital waveguide. Four presets: soprano, alto, tenor, and bass.
Vocal Synth
Section titled “Vocal Synth”Additive synthesis with 15 Kokoro voice presets: Aoede, Heart, Jessica, Sky, Eric, Fenrir, Liam, Onyx, Alice, Emma, Isabella, George, Lewis, plus choir and synth-vox sections. Features formant shaping, breathiness control, and vibrato. Deterministic output using seeded RNG.
Guitar engine
Section titled “Guitar engine”Physically-modeled plucked string synthesis with 17 tunable parameters (brightness, body resonance, pluck position, string damping, and more).
Guitar voice presets
Section titled “Guitar voice presets”| Voice | Character |
|---|---|
| Steel Dreadnought | Bright, balanced, classic acoustic |
| Nylon Classical | Warm, soft, rounded |
| Jazz Archtop | Mellow, woody, clean |
| Twelve-String | Shimmering, doubled, chorus-like |
Guitar tunings
Section titled “Guitar tunings”Eight tuning systems available: standard, drop-D, open G, DADGAD, and more. Use list_guitar_tunings to see all options.
Layered combinator
Section titled “Layered combinator”The layered engine wraps two engines and dispatches every MIDI event to both simultaneously. Useful combinations:
piano+synth— acoustic piano with vocal synth harmonyguitar+synth— plucked guitar with synthesized vocal layer
Tuning tools
Section titled “Tuning tools”All instruments support per-parameter tuning that persists across sessions:
tune_keyboard/get_keyboard_config/reset_keyboard— adjust and inspect piano voice parameterstune_guitar/get_guitar_config/reset_guitar— adjust and inspect guitar voice parameterslist_keyboards/list_guitar_voices— see available voice presets