I'm kind of a lazy, filthy casual music listener. Music isn't the most important thing in my life and it doesn't really define me. But there is one musical piece that immediately comes to mind when I'm asked about music that speaks to me or is uniquely important to me: Mozart's Sinfonia Concertante. No lyrics, no ideas per se. It's just the way it makes me feel. It's the most profound piece of music I've ever heard. If I were to die tomorrow, it's the last musical piece I'd want to hear.