This is a vibecoded website, which I generally look down on. But I made it for myself to use and don't hate it. So you might not hate it.
I been playing accordion for a while, and my next step is getting better at recognizing and playing chords and their inversions. My main goal is to be better at looking at sheet music and seeing how chords form melody.
Like at the beginning of Clocks by Coldplay. It starts arpeggiating down through an E flat major, first inversion. Then it moves to Bb minor, second inversion. And then F minor.
It's so much easier to look at melody in sheet music when you can think of it in terms of chords rather than just hunting note by note. It's like typing words instead of gibberish.
A second benefit is just understanding what notes are being played on the bass side. I like to play accordion with my wife while she plays guitar. There are an annoying amount of F to A minor chords in some of the songs she likes, and I'm slow at finding A minor. So I play C major and A, which is A minor 7th.
Rather than do flashcards to help me learn and identify chords, I helped Claude make this website.
It displays a chord in various ways, uses your microphone and listens for you to play it on the treble keys of your accordion. Select what kinds of chords you want to practice, and what inversions you want to work on. You can display any combination of chord name, notes on the staff, note names, and fingering.
Everything is in treble clef, because... accordion.
There's also a "Play along" section where you can work on practicing chord progressions. This might be useful if you play with a band. I thought it was a fun idea but that's not what I'm focused on right now.
Should work on computer or mobile, but didn't work on mobile Firefox for some reason. Needs microphone permission so it can hear what notes you're playing, but nothing else. All data is stored in your browser. It's meant to be used while playing your accordion.
Give it a shot and let me know what you think. It's open source and completely free.