sqsl Circle 4+

Geometry-based MIDI sequencer/controller.

Concept:
Place triggers on 2-dimensional ”timeplane” (as opposed to triggers placed on linear 1-dimensional timeline in normal sequencers). Place playhead - circular wave expanding through timeplane (as opposed to point-playhead advancing on timeline). When playhead encouters trigger, note is generated.

Rotate timeplane but keep playhead’s origin static - pattern evolves.

Interface: select mode on left side, right side and central part will show options/parameters available.

PLAY (playhead)
- Reach (how far playhead will propagate)
- Length (multiplier for note length)
- Octave transposition
- Divider (affecting speed/rate of playhead’s propagation)
- Channel (midi channel to which resulting notes are sent) or Mute state flip
- Rotate (will rotate Layer A or both layers by preset angle: 360/3, 360/4, 360/8 and 360/12 degrees)

When more that one option is enabled for above parameters, playhead randomly chooses one of them on start (reach, octave, divider) or when it encounters trigger (length, channel).

- Rate (playhead's propagation speed)
- Loop mode is activated by long touch when placing playhead

NOTE (triggers)
- Type I-VII (each type can have a specific pitch assigned)
- Type T (immediately restarts playhead that reached it)
- B layer (blue color)
- Note length
- Select type before placing trigger or use ADVANCE to automatically select next type after placement (type T excluded)
- Velocity is calculated based on trigger's distance from playhead

EDIT
- Clock parameter affecting timing of all elements
- Global MIDI channel offset
- Reposition existing playheads or triggers (touch and drag)
- Select playhead or trigger and edit playhead/trigger parameters

MUTE
- Mute/unmute individual triggers
- Unmute all triggers
- Ignore T triggers

ROOT
- Pitch origin from which type I and all the following types are calculated (transposes all types when changed)

PITCH
- Interval distance from root (for type I) or interval distance from previous type (in octaves and semitones)
- Separate set of 3 columns to set the octave (left) and semitone (right) distance
- First column represents +1 values, second +2 and third +4 (resulting interval is sum of activated columns)
- Scale Mode and Scale Pattern allows to set semitone interval distances to match scales (included patterns are: diatonic, melodic, harmonic major, harmonic minor and "heptonia tertia"). Octave distances are not affected.

SPIN
- Set angle directly for layer A or layer B (blue)
- Set rotation speed for layer A or layer B (blue)

MIDI
- Select current MIDI output

WRITE & READ
- Write current state for later recall
- Optionally read only pitch settings (root and pitch table) or only geometry (triggers and playheads) from presets
- Tap on WRITE when write is already active to enter ERASE mode

MOD
- Modwheel control (CC 1) per channel

Detailed description: https://www.seqsual.com/circle
Questions and feedback: https://www.seqsual.com/contact

Important notes:
- Circle does not make any sounds on its own, it generates MIDI messages (notes).
- Circle was designed for full-size iPads, not recommended to use on iPad Mini.