Is this okay?

Dear Paul Rosen:

I am not sure of github etiquette, but I like your library very much and would like to use it as part of a non-commercial application (rehearsing choir voice parts). There are a few tweaks I need to make:
1. overriding the embedding.
2. rendering voices in different colors
3. adding section markers

In today's commit, I've addressed (1) and also 'fixed' the behavior where barnumbers are assigned and displayed for each voice.
Thanks for your consideration.