what should be my first sentence?!!
This might be part of the problem, or it might not be. It might indicate that you are having trouble getting your groove on. When you pick up the guitar, you need to be able to get into a rhythmic state of mind. You need an awesome state of mind. Then, it does not matter what you play.
As for whether it should be a story, I'll say this: use anecdotes, not claims. That is how to use the rule, "Show, don't tell." But... do not give any unnecessary details. I don't think it should be presented like a story... but it might have little anecdotes within it.
Most importantly, stick to your purpose. Show that those activities reflect the same seriousness and passion that make it essential that they let you into this progam.
:-)