ARPJAM Studio vs Pendulums

No sequences. No loops. A generative synth that plays on by your rules. And you can play right along. Key, scale, density, complexity — just set the rules, and five machines (arpeggios, bass, drums and a sampler) keep playing, with a different phrase every time. What you shape is not a song — it is a way of sounding. No AI picks the notes: your rules and probability do. Move a slider and the sound changes shape without ever stopping. Density, contour, filter, tape movement. It is built so that nothing you touch can break it. Then play right along with your own fingers. The on-screen key pad holds only the notes of the current scale, so nothing goes off-key. Play ARP A, ARP B, BASS or DRUMS, or connect a MIDI keyboard. What you play can be captured into the looper. ■ Five machines • ARP A / ARP B — two independent arpeggio engines. Ten arpeggio types, including Phrase (builds melodies) and Fingerpick (fingerstyle guitar) • BASS — a dedicated bass engine (STEP / COMPLEXITY / OMIT / PATTERN) • DRUMS — a drum machine built from probabilities (KICK / SNARE / HIHAT / NOISE) • SAMPLE — record one bar, slice it, rearrange it • Chord progressions (presets / automatic / 16 custom slots), ten time signatures, six LFOs ■ Slice (SAMPLE) • Record one bar from a mic or line input, with count-in and click • Record the app itself (ARP A / ARP B / drums), and overdub onto it • Load audio files — and the audio from a video file • Up to 64 slices, ordered by the same rules as the arps: direction, reverse, octave, probability, groove • STRETCH (on by default) — change tempo without changing pitch • Its own filter, envelope and delay / reverb sends ■ Play • On-screen key pad — always in scale; play ARP A, ARP B, BASS or DRUMS • PEDAL (sustain) and a one-bar looper that records how hard you played and transposes with the chords • MIDI keyboard input (ARP A / ARP B / BASS; damper pedal, pitch bend, standard control changes) • XY pad and performance FX that work only while held ■ Sound (11 voices) • Piano — three velocity layers, stereo, damper release • Electric piano — harmonics shift with how hard you strike • Nylon-string guitar — synthesised with a physical string model • Marimba, kalimba, handpan and chime — struck instruments, measured from the real ones and synthesised • Waveforms (sine / triangle / saw / square) plus an acid filter • Filter, ADSR, five drive types, tremolo — shaped per voice • Delay, reverb, Glitch, Granular • DRIFT / FLUTTER — tape movement on the synth voices and the live input alike • Concert pitch A=415–444 Hz ■ Connect • AUv3 plug-in — as an instrument, as an effect, and as a MIDI effect • Ableton Link, MIDI Clock, MIDI out (ARP A / ARP B / BASS / DRUMS), LFOs and XY as MIDI CC • External audio input (line / microphone) • Background playback — keeps playing when you switch to another app (iPhone / iPad) • WAV recording and export One-time purchase. No subscription.

Twin Double Pendulums is more chaotic than my other engine using 2 Lorenz. This is more suited for Oriental music like Koto. The pendulums are released from the same angle, one of them offset by a ten-thousandth of a degree. Both drive a lead voice. While the runs agree the two voices land on the same note, so you hear a single line over a rolled arpeggio. As the gap opens the twin becomes a real second voice, chords swell in behind it, and once the runs have parted for good the whole band is in. Nothing is pre-recorded and nothing loops. Every release is new. THE SONG FORM IS THE PHYSICS There is no bar counter and no scripted arrangement — the piece is however long the pendulums stay together. Their separation is the structure: IN SYNC — lead and twin on the same note, one line over an arpeggio that re-voices itself every bar. DRIFTING — the twin splits into real intervals; chords enter and swell. DIVERGED — bass enters, the grooves open up, the mood engine wakes. Watch it happen: the gap is plotted live on a log scale with the running Lyapunov exponent beside it, so you can see the divergence coming before you hear it. DRAG THE RIG Pull the pendulum round to set the release angle and both twins let go again, from anywhere in the piece. Release it inside about 79 degrees and the motion stays regular, the twins never part, and the solo holds indefinitely — chaos is a regime, not a law, and the scope draws you that boundary while you drag. Outside it, the twin offset sets how long the solo lasts before chaos takes over, though only logarithmically: each extra decimal place buys about the same few seconds again. CHAOS PROPOSES, A POLICY DISPOSES The far bob's position proposes a region of pitches rather than one note. A Markov policy then decides what actually plays, learning from its own output and rewarding intervals that sound consonant. Slide BLEND to choose who wins. WHAT YOU GET • 26 scales — major and minor modes, pentatonics, blues, whole tone, harmonic and melodic minor, altered, both octatonics, and folk scales from Japan, China, Egypt, Spain, Arabia and Hungary • 8 accompaniment styles — chaos grooves, jazz comping with walking bass, stride piano, Alberti bass, classical, arpeggios, oriental rolls, ambient • Four sampled instruments — grand piano, koto, zither and shakuhachi — plus synthesised voices: soft piano, glass, strings, FM bell, AM organ, pluck, fat saw and more • 6 moods on a valence/arousal plane, from serene to tense, driving chord quality, register, tempo and note length • Expression built into the physics: ring, note bend, grace notes, and octave doubling called by the second bob • Live displays — the rig itself, the divergence chart, the note-probability distribution the engine samples from, and the mood point • Record a take and export it as a standard MIDI file to the Files app — lead, twin, chords and bass on separate tracks TWO AUDIO UNITS Pendulums ships as an instrument AUv3 and as a MIDI processor AUv3, so it can either play its own sounds or sequence any other instrument in your host. Lead, twin, chords and bass each send on their own MIDI channel, so one instance can drive four different instruments. Both Audio Units follow your host's transport and tempo — hit play in AUM, GarageBand, Logic, Cubasis or Zenbeats and it locks to the grid, on the bar line, even if you start mid-bar. One install registers both. CREDITS Sampled piano: Salamander Grand Piano by Alexander Holm (CC BY 3.0). Koto and shakuhachi: FluidR3 GM soundfont by Frank Wen (MIT). Zither: đàn tranh from the Versilian Community Sample Library (CC0).