What is on the written page is an approximation. This is really true of jazz. My instructor gives me jazz pieces to learn but won't tell me anything about them--just take them home and learn them. When I come back, I'm full of questions. One was a pattern that didn't really sound like anything. "You have to swing it," he said and played it the way a jazz bassist would play it. Smae notes but it sounded totally different and very jazzy. There's no real way to notate that. But now, whenever I see that pattern of notes, I know I have to swing it.

This thing I did at the coffeehouse, I was playing bass notes written for piano chords. I had to add in stuff that sounded double bassy because the straight notes off the page were too mechanical sounding. What was cool was that I could choose to play any note from a chord--not just the tonic. I could play a third or a fifth or a seventh which sounded very cool as long as I didn't overdo it and it gave the bass line some liveliness. Again, without the sheet music, I couldn't have done that.