I play trombone in marching band.
Last year, we played The Beatles for our field show, so Hey Jude was on there, sure enough. Anyways, my section leader played the opening solo of the song, and he failed to show on the homecoming game! A trumpet was frantically trying to learn the baritone part, and I just played it real quick off his music cuz I was bored. The Drum Major noticed, and press-ganged me into playing it for the show! I memorized it in 15 minutes flat, and played the crap out of it on the opening of the Song!
It was, by far, the greatest moment I've ever had playing an instrument!