Late response here that might not be useful to you, but I mostly use Google docs for lyrics (on both my phone and laptop) and tend to rely on bullets for altern

Late response here that might not be useful to you, but I mostly use Google docs for lyrics (on both my phone and laptop) and tend to rely on bullets for alternative lines. This is fine for 1-2 alternate versions of a given line, but would get clunky beyond that. I imagine if I wanted to fork a song further than just a few alternate lines, I could insert a 2-column table and continue the song in each column. It's rudimentary, but if you're worried that making your own software for it is just a form of advanced procrastination, something like Docs might be more manageable than Keep.