Database design dilema

Question

I have a small database dilema that I am trying to solve. I have 3 database tables: Lyrics, Tablature and Concert. Each table will hold a record for its own unique guitar tab, lyric or concert venue. I also have a comments table. I want users to be able to comment in each of those sections (Lyrics, Tablature, Concert) for a particular lyric, tab or concert...what is the best way to design the relationship with the comments table? Any ideas?? Thx