Great stuff by Sam Bellen, in which me mimics the effect-pedals for guitars:
Audio-effects is a JavaScript library to create audio effects using the Web Audio API. This library contains the Volume, Distortion, Delay, Flanger, Reverb, and Tremolo effects
He recently gave a talk about this at JSConf Budapest 2016 and at a local Fronteers Meetup:
Sidenote: To play audio in browsers I’m still a huge fan of Howler.