How can I get the "musical" chordname from a chord? about drywetmidi

[melanchall]

Hi Thomas,

Do you want to have method like ToMusicalName on Interaction.Chord or Parse one? At now you cannot get musical name neither for MusicTheory.Chord nor for Interaction.Chord. But it looks like useful feature. So I'll add it to my backlog. Thank you!

Max

[FischertBilligheim]

Hi Max,

Yes, this is the idea: With the chord-manager, I‘m getting all the chords - e.g. from a chunk. But I would like to show the „musical name“ of these chords in my GUI.
My proposal: Interaction.Chord.ToString() could do that....

Thanks to you, Max!
Regards
Thomas

[melanchall]

Thomas,

I'll implement the feature within this issue so please don't close it.

[FischertBilligheim]

👍👍

[melanchall]

Hi,

I've added method GetMusicTheoryChord for Interaction.Chord and GetChordDefinitions for MusicTheory.Chord. Last one is what you need.

GetChordDefinitions returns collection of "musical" definitions of a chord as instances of ChordDefinition class. Its ToString method returns musical name of the chord. Definitions are sorted by complexity so I suppose the first one is what you need.

For example, for chord A C E you'll get these definitions:

Am
Ab3
Adim#5
Aaugb3b5

Determining chord's definitions is pretty tricky. I don't use chords tables, the library tries to infer definitions algorithmically, so I sure there are errors and some chords may not be analyzed correctly (or analyzed at all). Please test the new API and if you'll notice issues, report me.

[FischertBilligheim]

Great, thanks a lot!! I will test it and give you response!!
Best regards
Thomas

[FischertBilligheim]

Hi Max,

in a first test, I used the following code:

        _IEnumerable<Melanchall.DryWetMidi.Interaction.Chord> chords = gActTrack.GetChords(20);
        foreach (Melanchall.DryWetMidi.Interaction.Chord chord in chords)
        {
                if (chord.Time + chord.Length > nt && chord.Time < mt)
                {
                    Melanchall.DryWetMidi.MusicTheory.Chord mChord   = chord.GetMusicTheoryChord();
                    IReadOnlyCollection<ChordDefinition> musicChords = mChord.GetChordDefinitions();

                    if (musicChords.Count > 0)
                        utils.DrawChord(chord.Time, musicChords.First().ToString(), Color.Red);
                }
        }_

I showed the result in my current implementation of my midi-editor/sequencer (red line on the top)

You see a chord-track of the song "Angel of Harlem from U2". The first chord has the notes "E,C,G,E,C" - I would expect, that this is the Chord "C-Maj", but not "C7#9#7"....

Another result:
I cannot call these new methods in my draw-routine - the redraw is far too slow now.....

[FischertBilligheim]

Hi Max,

additional hint:
If I'm using this code:

        _IEnumerable<Melanchall.DryWetMidi.Interaction.Chord> chords = gActTrack.GetChords(20);

        foreach (Melanchall.DryWetMidi.Interaction.Chord chord in chords)
        {
                if (chord.Time + chord.Length > nt && chord.Time < mt)
                {
                utils.DrawChord(chord.Time, chord.ToString(), Color.Red);_

this is the result:

And this works fast enough in the Paint-method......

[melanchall]

Hi Thomas,

Thanks for your tests. It seems it would be better to analyze chords by tables :)

But I have a couple of comments:

• First chord is C E G C E. C chord is C E G. With addition of E and C on top of it still C chord?
• chord.ToString() just prints notes of a chord so it's not a name of chord.

[FischertBilligheim]

Hi Max,

To be honest: I have not much knowledge about music theory. But I assume, that if there are duplicate notes in different octaves ( like in my sample) - these notes can be ignored.

I think a good reference is here:
http://www.sengpielaudio.com/ChordNameFinder.htm.

To the second comment:
Yes, sure - I’m aware of that. I only mentioned that to give you the info, that this is fast enough to call these functions in the paint/redraw method.

[melanchall]

Yes, I'm looking to the same article :)

Well, I'll try to rewrite my methods to use chords tables prior to current algorithm.

[FischertBilligheim]

Maybe that can help:

https://github.com/DrA1ex/GuitarHelper/blob/master/PianoKeyEmulator/Chords.cs

[FischertBilligheim]

I meanwhile tested the „PianoKeyEmulator“-Approach - it looks pretty good.
I‘m currently adapting the algorithm to the classes of drywetmidi.
If you are interested, I can - if I finished - send you the implementation, you can adapt it to your coding-style, and integrate it....

[melanchall]

Hi Thomas,

I've removed GetChordDefinitions method and added GetNames one. It returns list of names of the chord using chord table. At now the table is not complete but I'll add more records to it.

Also I asked my friend from symphony orchestra about duplicated notes in a chord. You're right, C E G C E is indeed C chord, it doesn't matter how many duplicated notes are on top of C E G triad.

Please test new API. I'm waiting for your feedback.

[melanchall]

Added more records to chords names table (CNT).

[FischertBilligheim]

Hi Max,

I did a first short test: It looks better, and I don't have Performance issues any more…

But furthermore a lot of chords are not recognized:
e.g: E,G,C:-> C-Maj
C A,F -> F-Maj
D#,G#,C -> G#

The mentioned "PianoKeyEmulator" has an interesting approach:
"Permutations" of the chords are generated and tested - maybe you can have a look to that:

It's the first result from me from today... it's a in-work version:

MidiChords.zip

[melanchall]

Thanks Thomas. Yes, these permutations are called chord inversions. I'll include them to the CNT lookup. But I think it will degrade performance. I'll test and let you know.

Thanks again.

[FischertBilligheim]

Thanks to you, Max!! 👍

[melanchall]

Added chords inversions to CNT lookup. @FischertBilligheim Please check out.

[FischertBilligheim]

Hi Max,

wow - the current implementation is really great!
Congratulations - how you realized that new functionality in that short time!!

Best regards
Thomas

[FischertBilligheim]