Even though Journey's Don't Stop Believin' was written in 1981, it's still being played, covered and talked about on television, in films and on tour 30 years later. The song, it turns out, is also the most-downloaded song in the 20th century, garnering more digital sales than Stairway to Heaven, Smells Like Teen Spirit, Like a Rolling Stone or Hey Jude. That's pretty stiff competition. Check out the clip below and see why this song still has legs three decades later: