Live editing

miditool run watches the config file it loaded. The edit loop is: play with one hand, tweak the file in your editor, save, hear the change. No restart, no silence.

What happens on save

• The file is re-parsed and a new effect graph is built.
• The new graph takes over on the next event. Notes already sounding finish under the mapping that opened them, so nothing sticks and nothing cuts off mid-ring.
• Effects and their parameters, scenes, and tempo all reload this way.

Two settings need a restart because they change the ports themselves: input and output. Edit those, then stop and rerun.

Broken edits are safe

If a save does not parse or fails validation, miditool prints the error, with the offending line, and keeps the previous graph running. Sound never stops because of a typo. Fix the file and save again.

config error in miditool.kdl:
echo: decay must be greater than 0 and at most 1, got 1.4
(previous config still running)

A practice loop

Seeded effects make live editing a compositional tool. Try this: run a scrambled keyboard,

miditool.kdl

input "Roland"

shuffle-lock seed=42

and while playing, change seed=42 to seed=43, save, and the instrument becomes a different (equally stable) scramble on the next note. Roll through seeds until one sings, then keep it; the same seed is the same instrument forever.