This song was the very first single by the band Chicago. It did not become a big hit. But it's good for teaching people about suspended 4th chords and resolving them to the major chord.
I played trumpet in high school. Back then, in addition to the usual piano-guitar-vocal books of sheet music, Chicago would also publish books of sheet music called "sketch scores", which would include all the brass parts. I still have the books that cover their first nine albums. As a result of being a trumpeter and having these books, I'm only willing to play a Chicago song on ukulele if I can fit a lot of the brass part into the arrangement.
