Thanks again, Peter. I'll look for both of these. Leeneia, I can and do sing along with things and harmonize, but I have a habit of doubling the tonic periodically, or sometimes the fifth. If I write out the melody, I can write two harmony lines that work, but I am much more of an aural person -- what I want is to get better improving harmony lines in vivo -- at singing sessions, or as a harmony singer for someone. I find it helps if I slow things down and hold notes against notes, but I cannot do that with other people's recordings or in singing sessions.

I am also interested in improving my overall ability to listen to details (guitar parts, fiddle parts, where the harmony vocals are in a mix)