Pain Perdu — Hidden LSDJ Tricks EP1: Instrument Retriggering (video, 2016)

The first of six episodes, framed as "hidden tricks in LSDj that are probably in the manual but not necessarily gone over in enough detail". The subject is one fact with a long tail: a note and an instrument number are independent, and the instrument number is what re-triggers everything the instrument owns.

Key claims#

• "You don't necessarily need to have an instrument value next to a note for it to produce sound." A note alone plays with the settings already running. The instrument number "reads the settings from here and triggers it every time it reads the instrument value" — envelope, table, and on the wave channel the synth's wave cycle.
• The envelope demonstration: a pulse instrument with a rising envelope (starting at 1, rising at speed B). Put the instrument number on every note and the envelope restarts from the bottom each time; delete it and "my envelope will start from here and keep rising even though a new note is inputted".
• Musical use: trigger every second note, or once on the beat, and a run becomes an arpeggio that swells across the bar and resets on the beat — "a nice legato arpeggio with the rising envelope that only needs one instrument value each time you want to make it rise".
• Cheaper, too: leaving instrument numbers off is "a nice technique for you to save space, save blocks and save CPU usage".
• Tables retrigger with the instrument, since the table is part of the instrument's settings — an unretriggered table keeps running through the following notes. With TABLE set to AUTOMATE the table advances per instrument value rather than per tick, so the classic L/R panning table gives L R L R when every note is triggered, and L L R R when only every second note is — the same table, a different rhythm (stereo-panning).
• The wave channel is where it pays off. A wave instrument set to PINGPONG with LENGTH F and a slow SPEED evolves over many notes — but its wave cycle is retriggered by the instrument number too, so "I cannot actually hear the full range of wave cycles". Trigger it once every four notes and the whole cycle is audible: "if you have something that cycles through waves really slowly you can have rhythmically evolving waves that are really interesting".
• The kick problem: everybody puts kicks on the wave channel, and a kick is a different instrument, so it re-triggers the evolving lead when the lead comes back. His fix is to shorten the cycle to fit the gaps — LENGTH 3 with SPEED 6, so a frame changes exactly every 16th note and the whole cycle completes between kicks.
• His throwaway kick recipe, for the demonstration: note C-6, PLAY MANUAL, triangle wave, VOLUME 40, killed from the table at step 5, "just before the next sixteenth note triggers".

Practical takeaways#

• Type the instrument number only where you want the sound to restart. Everywhere else it is noise in the pattern and a restarted envelope you did not ask for.
• AUTOMATE + sparse instrument numbers turns a table into a per-phrase rhythm rather than a per-note effect.
• On the wave channel, match the synth's cycle length (LENGTH × SPEED) to the space between the drum hits that interrupt it.

Notable quotes#

"It's really important to know that instrument and note are actually independent."

Relevance to the wiki#

The wiki knew that omitting the instrument number slurs a note (lead-articulation); this is the general rule behind that, with envelope, table, AUTOMATE and wave-cycle consequences.

To verify#

• The kick values (C-6, VOLUME 40, kill at 5) come from an auto transcript of a fast demonstration and are illustrative, not a recipe to copy exactly (unverified).

Pages touched#

retrigger · instrument-tables · lead-articulation · wavetable-programming · stereo-panning · instrument-envelopes · lsdj · pain-perdu