Photo: Claudia LopezI deejayed a Valentine's Day party at the Horseshoe Lounge on Saturday. The bar had a great vibe, as always, and the ample crowd was in the mood for a good party. It was the first time I ever had to play music for four and a half straight hours, and I was initially worried that I would: a) run out of songs I wanted to play, or b) not have the right music to keep the party going. I underestimated both the strength of my music collection and the self-sustaining power of a party