Wad
Web Audio DAW. Use the HTML5 Web Audio API for dynamic sound synthesis. It's like jQuery for your ears.
Pizzicato
Library to simplify the way you create and manipulate sounds with the Web Audio API.
Midi Writer Js
♬ JavaScript library providing an API for programmatically generating expressive multi-track MIDI files in browser and Node.
Jsmediatags
Media Tags Reader (ID3, MP4, FLAC)
Tone.js
A Web Audio framework for making interactive music in the browser.
Speak.js
Text-to-Speech in JavaScript using eSpeak
Tuna
An audio effects library for Web Audio, made by www.dinahmoe.com
Midi.js
Making life easy to create a MIDI-app on the web. Includes a library to program synesthesia into your app for memory recognition or for creating trippy effects. Convert soundfonts for Guitar, Bass, Drums, ect. into code that can be read by the browser. Supports multiple simultaneous instruments and perfect timing.
Teoria
A JavaScript music theory framework.
Sound Manager 2
A JavaScript Sound API supporting MP3, MPEG4 and HTML5 audio + (experimental) RTMP, providing reliable cross-browser/platform audio control in as little as 10 KB. BSD licensed.
Pedalboard.js
Open source JavaScript framework for developing audio effects for guitars using the Web Audio API.
Audiolet
A JavaScript library for real-time audio synthesis and composition from within the browser
Sound JS
A Javascript library for working with Audio. Features a simple interface as the front end to multiple audio APIs via a plugin model. Currently supports HTML5 Audio & Flash.
Webaudio.js
web audio library for games
Mp3.js
A JavaScript MP3 decoder for Aurora.js
Audio.js
A cross-browser javascript wrapper for the html5 audio tag
Flac.js
FLAC decoder in JavaScript