I was listening to a U Tube video recently about Singing Harmonies .A nice tip I heard was to take tunes that you know and try to play them in several different keys by (ear) . Many tunes will be possible .Try in the keys of C,G,D.A and F to start with .This teaches you that once you find the start note where to find next note .Once you have done that you can also sing and try to find the chords that go with the song . Again do it in several keys just playing Chords .Hope that helps . Bob