Is there a comprehensive chord guide for concertinas such as for piano? I have seen some basic chord guides for concertina on the web, but nothing that covers complex or extended chords such as Bm7b5. I have been using a chord guide for piano, but you have to figure out where the corresponding notes are on the concertina. Also, I rarely play the complete chord, just enough of the chord to imply the overall chord tone, such as root and third or root and fifth. I play English, not duet, so I don't know how well this applies to duet, but I would think the general approach would be similar.