I've photographed Harmonium for a couple years. It's a full day of music and fun; of course, I'm working throughout it. The main and community stages themselves are enough to keep me busy; despite this, last year was the first that I decided to work the edges a bit. Lingering in the musicians' tent, watching load-in and preparations, wandering around the audience--any activity apart from the stage was what I was interested in.
I also decided to camp overnight, which meant I was present for the post-festival jam session. Listening to these musicians--only some of whom knew each other, musically or otherwise--was a real joy. They seemed to have endless amounts of energy.