BSharp - Make beautiful music with the webkit audio api

BSharp is a library that abstracts the webkit audio api, and adds a more "musical" interface for working with oscillators.

Classes

• BSharp.Song - Base class for creating a song from sound nodes and attaching them to a context; has play and stop methods.

• BSharp.SynthSong - Builds on BSharp.Song using a list of note objects to contructor oscillator nodes.

Methods

• BSharp.createSynthSong(notes) - Convenience factory method for generating a SynthSong.

• BSharp.buildSequence(tuples, defaults) - The first argument should be an array of arrays, each of which can have 3 arguments: 0. Note name - The name of a note in scientific pitch notation i.e. "C5"

  1. Length - The length of the note; by default a length of 1 will produce a 1 second long note, but you can use BSharp.applySequenceTempo to the notes returned by BSharp.buildSequence so that a length of 1 can represent one beat instead.
  2. Rest - Adds a rest at the end of the note, subtracted from the length. Defaults to 0.
  3. Config - An object with any additional properties you want added to the note object. Currently not very useful, but I plan to added effects, and volume adjusting capabilities, so those additional options could be included here.

  You may also pass in a defaults object as a second parameter, useful for specifying a default note length or rest to add spacing between notes.

• BSharp.applySequenceTempo(notes, tempo) - Adjust note lengths and start times so that a length 1 is becomes 1 beat at tempo bpm.

• BSharp.getMajorChordNotes(note, length, start) - Create chord notes for a major chord that you can combine with other notes and sequences to make songs.

• BSharp.getMinorChordNotes(note, length, start) - Same as above, but minor chord.

• BSharp.getScaleChordNotes(note, steps, length, start) - Create chord notes where steps is an array of increments of half steps that will be used to calculate the 1st, 3rd, 5th and octave notes of a scale, the create note objects from those values.

• BSharp.getMajorChord(note, length, start) - Creates a SynthSong object of a major chord. Intended for demo puposes.

• BSharp.getMinorChord

• BSharp.getScaleNotes(note, steps, length, start) - Create note objects representing a scale.

Properties

• BSharp.steps - An object with properties that are each an array of increments in half steps representing the steps of a scale. These arrays can be used to construct scales and chords when combined with BSharp methods.

• BSharp.ctx - A webkitAudioContext instance that is attached to each Song. You can override this with a different webkitAudioContext if you have the need (you can also override the ctx property on Song objects).

I would like to provide more song construction tools and effects in the future, as well as a demo application to play with this stuff with some sort of UI.