The other day, while working at The Store, I found myself humming along to the pop song that was issuing from the loudspeakers. (Our music selection focuses on inoffensive popular music -- Celine Dion, Elton John, the occasional Jim Croce song.) I actually hummed along with this particular song for a minute or two before I stopped, realizing that I couldn't be humming with it since I had never heard it before. How on Earth could I be humming it, then?
When the song reached its chorus for the second time, I realized what was happening. I wasn't humming along with the song at all; I was humming along with the song's melody, which I know extremely well, since it is from the third movement of one of my absolute favorite works of classical music ever, Rachmaninov's Symphony No. 2 in E-minor.
Popular song writers have, of course, been mining the classical repertoire for years, almost as long as popular music has existed in the first place. And before that, even classical composers would borrow from one another. As a classical music lover, I really don't find this practice at all offensive. A great song needs a great tune, and a great tune needn't be used exactly once. (However, the use of a great tune in a bad song annoys me. I have no idea if the Rachmaninov-based one that I heard qualifies, since I couldn't make out the lyrics.)
In trying to Google what the song I heard might be, I found this handy listing of pop songs that have drawn from classical music. It's an interesting list -- I had no idea that Neil Diamond's "Song Sung Blue" came from Mozart -- but it doesn't include the song I heard, alas. I will update later if I find it.