I have long been fascinated with the piano riff that begins Elton John's famous piece Someone Saved My Life Tonight. The first few bars use a diatonic pattern in which the bass lines follow the notes on the scale and these notes form the basis for the chords played with the right hand. From the beginning you can't exactly tell what key the song is in. Elton's purpose is to keep the listener off balance as to the tonal center of the piece. Combine this base pattern with a brilliant melody, and you've got a monster hit from a musical genius. The song was released in 1975 when I was a senior in college and playing piano duets with my roommate from Brazil in the Biola chapel services. I love playing this riff to this day as it requires extreme concentration with your left hand as you play the bass lines. The piece is a masterful arrangement to be sure.