Support for combinations, e.g. Amaj7sus2

[hyvyys]

Currently it seems there's not support for advanced chords like Amaj7sus2, C6add2, etc.

[hyvyys]

I checked out /packages/chord-dictionary/data.ts. I thought that tonal uses an algorithmic approach, not a dictionary. In see there's some heavy-weight music theory. In that case I'm not sure my chords qualify as proper real chords, but I swear I am able to play them on my guitar and even use in some songs ;D

Also, is (b5) on its own a valid chord, e.g. F(b5)?

[hyvyys]

Also, it would be nice to have an extra field in the chord object requiredNotes, typically the same as notes but often with omitted 5P.

[hyvyys]

From https://en.wikibooks.org/wiki/Music_Theory/Complete_List_of_Chord_Patterns#Alterations

The table below shows common altered chords:
....

The table itself only contains examples.

BTW I would not trust a wikipedia article to be complete, especially if its title says so. ;)

The required notes I was talking about would omit the steps that are parenthesized in the article.

[bitworking]

Hey, I found this issue because I'm developing a MIDI chord detection program. I also try to use this chord data from the wiki article. What I've done to allow these optional notes is to encode it as bitmasks and use bitwise operations. Maybe it's interesting for you:

const chordData = {
  // 1 3 (5) 7
  name: 'maj7',
  mask: 0b111111101111,
  bits: 0b100010000001,
};

// create integer from string bit representation, in this case 1 3 7

const chordBits = parseInt('100010000001', 2);

// compare to data

if ((chordBits & chordData.mask) === chordData.bits) {
  // matched
}

Nevertheless, I will probably no longer pursue this approach and switch to an algorithmic approach, because it would be very hard to implement inversion and slash chords in this way. The best library for inspiration that I've found is this: https://github.com/t-bre/MIDIAnalyser/blob/master/MIDIAnalyser_2-0-0/MIDIAnalyser/ChordAnalyser/ChordAnalyser.swift

It gets the intervals from the chord and find the tonality and all extensions by that. It also processes all inversions and it seems it works with slashed chords, too. But I don't know how good the namings are in the end or if these chords all make sense.