Terry, Shirley and Tom

In The Wall Street Journal last week, my latest "Anatomy of a Song" column was on Earth, Wind & Fire's September (go here). The song was released in late 1978 and became a No. 8 Billboard pop hit in early '79 and climbed to No. 1 on Billboard's R&B chart. The song has three credited songwriters—the band's guitarist Al McKay wrote the music, and the lyri…