Passion.I love to sing. I am also not a singer, though I know how to sing right notes and belt it when I want to. For me though, when I sing I have to have passion. I can't/don't sing if I've had a blah day where everything has rated a 5/10 the whole day. I sing when life gets me down. Whether I'm pissed depressed or disappointed singing always seems to help. I love screaming along to linkin park or rise against when I pissed, I really channel my anger and let it loose. When I'm sad I love yellowcard. They have happy songs and sad songs, but either way I love singing along and it always cheers me up.
I used to sing alot more. When I was with my girlfriend we would always sing together. I have never sung better or more passionatly then with her. Not only would we sing as friends, but i'd also sing of my love to her. Those were happy days.