Introduction to Sound Synthesis Shaping control signals
Hocketing
Hocketing shares a single melody between several voices so that each plays only some of its notes. The melody moves from voice to voice as it plays, and each voice's note can continue through its release while another voice plays the next note.
The word comes from hocket, a technique in thirteenth- and fourteenth-century European polyphony in which singers alternated notes, each falling silent while another sang. Music from other traditions uses the same principle. In Balinese gamelan, pairs of instruments play interlocking patterns that together make one line, and the notes of the Andean panpipes called siku are split between two players, each of whom plays the notes the other's instrument lacks.
On a synthesiser, hocketing means sending each note of one sequence to a different voice. The pitch can go to every voice at once, and only the gate is shared out, so each voice plays only the notes whose gate it receives. On a modular synthesiser that is a sequential switch or a gate distributor after the sequencer's gate output; in software it is a note-routing setting. The tool below shares one line between three voices with different timbres, placed left, centre and right.
Hocketing one line between three voices
One eight-note sequence is shared between three voices, each with its own timbre and position in the stereo field. The sharing can go in turn, at random, by pitch range, or not at all.
Listen for With all voices together, every note sounds in all three timbres at once. In turn, the line moves left, centre, right and round again, and because each voice has its own release, notes ring on under the following ones. By pitch range, low notes always come from the left voice and high notes from the right. Raise the release to hear each voice overlap the next.
Ways to share the notes
Taking turns, also called round robin, gives each voice every third note with three voices, so the line circles between them at a steady rate. Eight does not divide by three, so an eight-note sequence shared between three voices gives each voice a different set of notes on each pass, and the same note returns to the same voice only every twenty-four notes. Sharing at random sends each note to a voice chosen afresh, so the assignment of notes to voices does not repeat. Sharing by pitch range sends low notes to one voice and high notes to another, which splits one line into what sounds like a bass part and a melody.
Overlapping releases
Each voice has its own envelope, so when the line moves on to the next voice, the last note of the previous one keeps ringing through its release while the next voice plays. A single voice cannot do that, because each new note restarts its envelope. The result sounds like several players rather than one, even though only one line of notes was programmed. A polyphonic synthesiser also shares notes between voices and lets one note's release overlap the next, but its voices are usually set identically. Hocketed voices are usually set differently, so the movement of the line from one voice to another can be heard. The next chapter covers logic modules, which build new gate patterns from existing ones and are another way of choosing which voice plays which note.
Common questions
What is hocketing?
Hocketing is sharing a single melody between several voices so that each plays only some of its notes, with the voices taking turns. The technique is centuries old in vocal and instrumental music, and on a synthesiser it is done by sending each note's gate to a different voice.
How do you hocket on a modular synthesiser?
Send the sequencer's pitch to every voice and send its gate through a sequential switch or a gate distributor, so that each note's gate reaches only one voice. With two voices each one plays every second note, and with three every third, each with its own timbre and envelope.
What is the difference between hocketing and polyphony?
A polyphonic synthesiser shares notes between voices so that several can sound at once, and its voices are usually identical. Hocketing shares a single line between voices that are deliberately different, so the melody moves between timbres and positions as it plays.
Published Glossary