accidental-value

accidental-value

A simple module for parsing chord symbols, both Jazz and Classical. Parses correctly everything from simple power chords (D#5) to chords you'll often find in the real book (G7#5, Dm7b5) to crazy chords like Fsus4maj#11 or Cm13b5#9.

Note that this module only parses the chord symbol (that is the part of the chord string that does not include the root, and thus returns relative intervals from which the chord can be constructed with any root.

usage

var accval = require('accidental-value');

accval(accidental)

Returns the value of the accidental from the table below. This is useful for manipulating notes and intervals.

• 'x' = 2
• '#' = 1
• '' = 0
• 'b' = -1
• 'bb' = -2

accval.interval(accidental)

Returns the relative interval (given in [octaves, fifths] format) of the accidental. E.g.:

accval.interval('#') // [-4, 7]
accval.interval('bb') // [8, -14]