I sat down with a JavaScript project idea in mind, and had a major hurdle to jump right at the top: Building a sampler that I could load my own audio samples into, making them playable with the computer keyboard, with some basic filters and delays to fiddle with.
https://medium.com/geekculture/building-a-modular-synth-with-web-audio-api-and-javascript-d38ccdeca9ea