stradella

a chord on every breath

20 HP

A chord voice of free reeds: an accordion's left hand. One sequencer lane presses a button on the board, and the chord's reeds all sit in one octave, so every chord lands next to the last. The bellows are the air: worked gently it sits under a voice; squeezed hard it barks.

The STRADELLA panel: black, and in gold dots an accordion's bass end: six slanted rows of twelve round buttons across the top, a reed block of brass plates and steel tongues down the middle, the pleated folds of the bellows running across behind. Jacks down both sides, the knobs between.

Turn a knob: drag it or tap either side of it, roll the wheel over it or use the arrow keys; a double click puts it back. QUALITY is a switch: it clicks from chord to chord the same ways. In Your hand on the bellows, drag the folds at either side down to push and up to pull, or tab to them and use the arrow keys. The patches step on by themselves until you touch anything.

A slow, dark loop at 84 BPM, a chord a bar from one sequencer lane, a kick and hats under it. Listen plays the patch from its top.

example patches

Everything STRADELLA does here is its engine as designed, running in your browser: the reeds, the bellows and the choosing of the reeds. The lane, the singer and the drums are a stand-in rack.

The board

An accordion's left hand plays chords from a board of buttons: twelve columns round the circle of fifths, six rows of single notes and chords. Here a lane's CV picks the column and QUALITY the button, and a button is a whole chord.

ROOT: 1 V an octave, 0 V is C. Only the note counts, not its octave: the board has one button a note.
QUALITY, an eight-stop switch: major, minor, seventh, minor seventh, major seventh, sixth, sus4, diminished. Major, minor and diminished are a button each; the four-note chords are two buttons that share two notes, as an accordionist presses them; sus4 is three bass buttons side by side.
QUALITY's jack: 1 V a step, added to the switch, so a second CV from the same lane plays the quality.
PRESS: the buttons held while the gate is high. Unpatched they're always held, and the chord follows the lane for as long as there's air.
The lights: the buttons pressed. The quality is a row, the root a column.

The reeds

One reed a note in an octave from E3, as each set of an accordion's chord reeds is one octave, so every chord comes out close and in the same place. Three more reeds either side let a voice step over the octave's edge rather than leap across it: on each change the voices go where they move least in all.
A note two chords share stays on its reed and doesn't speak again; the reed block's tongues show it, steady, while the new ones flare. The chords of UNDER THE HUM and HOME TO ROOST, played from one lane, come out voiced exactly as they were voiced by hand.
REGISTER moves the octave a semitone a step, from E2 to E4; its jack, 1 V an octave.
MUSETTE: fully left one reed a note; turned up, two more, one sharp and one flat, beating against it, up to 30 cents apart at full. Its jack, 0 to 5 V across the knob's travel.

The bellows

BELLOWS, the big knob: how hard they're worked. With a little air the reeds speak late and soft; at noon they're there in about a twentieth of a second; at full they speak at once and bark.
BELLOWS's jack is a hand on the bellows: positive pushes, negative pulls, and how far from 0 V is how hard, added to the knob. A change of sign is a turn.
SHAKE: how long the bellows' travel lasts, from 40 seconds to an eighth of one. When it runs out they turn: the air goes through nothing for a moment, the valves click, and the other reed of each note's pair speaks. Under three o'clock it saves its turns for a change of chord; past it they come as fast as the air runs out: the bellows shake.
The lights: the folds glow with the air in the bellows, and the brightest one climbs as they open and comes down as they close.

The bass

BASS: the bass row's root under the chord, low and in octaves. Past four o'clock each press of PRESS alternates the bass and the chord, root, chord, fifth, chord: the oom-pah.

What comes out

LEFT, RIGHT: the reeds, spread a little by pitch, the bass in the middle. Summed, they're the same chord.
LOW: the bass on its own. Patch it and the bass leaves LEFT and RIGHT.
TURN: a trigger at every turn of the bellows.

Specs

Format

Width: 20 HP
Controls: a big knob, 4 knobs, an eight-stop switch

Inputs

ROOT: V/OCT, 0 V = C
PRESS: gate
CVs: QUALITY (1 V a step), BELLOWS (−5 to +5 V), MUSETTE (0 to 5 V), REGISTER (1 V an octave)

Outputs

LEFT, RIGHT: audio, the chord
LOW: audio, the bass
TURN: trigger