This might generate a few thoughts. You know, when You're a member of a band, the actual 'sheet music' is a constant. Players come and go--in most cases; but, the same sheet music remains for all those who pass pass through to READ. Open a big band folder, and rarely--unless it was just passed out--is a piece of music void of 'stuff' other than title, credits, notes and staves, etc.
Along with sometimes being raggedy, frayed, coffee stained--don't leave the cup there; the stand is already tilted and Murphy's law lurks...:-)}--, ...cigarette burned or otherwise soiled; are the marks, note changes,etc. made by previous players of the part. Then, it can go off the hook--phone numbers, meaningless scribbles, drawings--including eyeglasses with dot eyes(helpful here because it noted a passage to 'watch out for'), cartoons, jokes, signatures, dates,etc.
One thing I found funny, and always remember; is a prior player had crossed out the title 'Eleanor Rigby' , and wrote--with a marker: 'Bilbo Bagby'................; go figure. I guess its a 'leaving your mark' thing.................:-)}
