cluster-fist

cluster-fist turns each note into a tone cluster: one finger plays a fistful.

Henry Cowell got these sounds with fists and forearms in The Tides of Manaunaun, notating bands of adjacent keys as single gestures; here the band comes from one key. Each note-on becomes width member keys drawn from the kind’s set: every key ("chromatic"), the piano’s white keys, its black keys, or the members of a sieve (kind="sieve" sieve="..."). The anchor places your key at the bottom, center, or top of the fist, and the cluster fades away from it: the played key keeps your velocity, and the other members fade by rank in order of distance from it, the nearest scaled by rolloff, the next by rolloff squared, and so on outward (ties break toward the lower key). The played key is always included even when the set does not contain it (a black-key cluster anchored on a white key keeps its white anchor), and a side that runs off the keyboard, or past a sparse sieve’s last member, truncates, shrinking the cluster.

The mapping is deterministic, no seed. The member keys are remembered per held note, so the note-off releases exactly the keys that sounded; nothing hangs.

Parameters

Parameter	Type	Default	Range
width	integer	4	2..=12 keys
kind	string	"chromatic"	"chromatic", "white", "black", "sieve"
anchor	string	"center"	"bottom", "center", "top"
rolloff	number	0.8	0..=1
sieve	string	required with kind="sieve"	non-empty sieve expression; only allowed with kind="sieve"

Example

miditool.kdl

input "Roland"
output virtual="miditool Out"

cluster-fist width=6 kind="white" anchor="bottom" rolloff=0.7

Every note becomes six white keys rising from it: your melody rides the bottom edge of a diatonic fist. This is how the cowell scene of examples/clouds.kdl starts.

Try this

Clusters that are chords. Drawn from a triad sieve and anchored at the top, the fist arrives as a spread voicing under each melody note:

cluster-fist width=5 kind="sieve" sieve="12@0|12@4|12@7" anchor="top" rolloff=0.6

Then go the other way entirely: kind="black" width=12 anchor="center" rolloff=0.9 is a forearm’s worth of black keys, pentatonic slabs from single touches.