The song that silenced the cappuccino machine. It was chilly in Manhattan but warm inside the Starbucks shop on 51st Street and Broadway, just a skip up from Times Square . Early November weather in New York City holds only the slightest hint of the bitter chill of late December and January, but it's enough to send the masses crowding indoors to vie for available space and warmth. For a musician, it's the most lucrative Starbucks location in the world, I'm told, and consequently, the tips can be substantial if you play your tunes right. Apparently, we were striking all the right chords that night, because our basket was almost overflowing. It was a fun, low-pressure gig - I was playing keyboard and singing backup for my friend who also added rhythm with an arsenal of percussion instruments. We mostly did pop songs from the '40s to the '90s with a few original tunes thrown in. During our emotional rendition of the classic, "If You Don't Know Me by Now,"...