O Christmas Tree question about chords used
Hi Willie, I really enjoyed your lesson on "O Christmas Tree". There were two chords that i loved but didn't understand their harmonic function and would like information about them. In measure 13 the B minor 7 flat 5 and the B flat minor 6. They are substituting for the F Major 6 and G minor 7 that had been the chords earlier in the song. The sound of the B minor 7 flat 5 is that of a tri-tone substitution but I don't really know. When you get a chance, would you talk about how these two chords fit into the key. Thanks for all you do, Lonnie.