I love this post. I always sing along to:

The Entertainer - Billy Joel

Bridge Over Troubled Water - Simon and Garfunkle

I'm Goin' To Carolina - James Taylor

Rocky Mountain High - John Denver

This Song Has No Title - Elton John

Instrumentals that I can only hum along with:

Classical Gas - Mason Williams

Funeral for a Friend - Elton John

Root Beer Rag - Billy Joel

La Chanson de Claudine - Mason Williams

Anji - Paul Simon

We agree on "Let It Be"