I'm fairly new to the accordion and have played piano in the past. I mostly play by ear and just trying things out. I have a 120 bass piano accordion.
When I play the chord buttons, I don't use the diminished chords row, because I don't know an easy reason for using them. In other words, while I can see that I can create a minor seventh chord using the major chord button with the sixth in the bass, I can't see an obvious similar fancy chord using the diminished row. It seems like it would only be useful for the occasional alternate 7th chord, as I already have a row for 7ths.
Please could someone help me understand some good bass button combinations using the diminished row, or something to practice using that row which would help me incorporate it more naturally into my playing.