if there has been one band which has just blown me away through one performance it's been The Who.
I remember when I was in high school my father has a cassette copy of their concert album "Live at Leeds"....if I remember correctly, I wasn't necessarily impressed.
But as time has gone on, I grew more and more impressed with their energy, their musicianship, their passion. Partially because of their records I came to believe that those three values are the cornerstone of Great Music, and whenever I've listened to music I've used those values as a system of evaluation. And on my own music, while I hope I don't just play to emulate The Who's interpretation of those values, I always tried to push myself to play at their level.