# Instrument III, Percussion Generator There's a common pattern I use a lot when creating procedural patches. This pattern has two parts, and forms a sort of rudimentary groovebox. > [!cite] Lore > ![[3-apostate.png]] > Apostate (art by Dead Carcosa) First, I create a sequencer that repeats every 4 or 8 notes, and I have the notes change occasionally, creating a slowly evolving melody. I will have other parameters I modulate similarly slowly. Stuff like gate, velocity etc. Second, I use some sort of versatile tone generator that can generate noisy sounds as well as melodic sounds. FM, PM, Karplus-Strong, Subtractive, and noise through a bandpass filter or resonator are all possible choices. ## Bandpassed Plonk Generator From [[Signal Music II, Beat and Rhythm]]. This example uses a noise source through a bandpass filter. The frequency and the resonance of the bandpass filter are slowly changed over time. This creates rhythmic "plonk" sounds that sound intentionally-created, since [repetition legitimizes](https://www.reddit.com/r/AdamNeely/comments/u267rq/origins_of_repetition_legitimizes/). > [!example] > ![[image-15.png]] > A synth that generates slowly-evolving beats out of filtered noise.