If you ever want to make yourself feel old (and, really, why would you want to do that?), check out the "Oldies" section of Apple Music or the "Classic Oldies" playlist on Spotify.

The music of our youth is now considered "Oldies." We saw a Ramones song on one of the playlists and nearly had a panic attack. (That sounds like a Ramones song, actually.)

So what is "Oldies" music? Is it a specific sound? Is it simply a chronological classification for any song more than 40 years old? 

The following musical legends are now all classified as Oldies. Do you think of them as Oldies?