Written as the title track for Elvis' third movie, "Jailhouse Rock" is one of rock & roll's great irreducibles. Written by Jerry Lieber and Mike Stoller, the song sports one of rock & roll's most simplistic riffs, one that can be played by even the most stylistically challenged of musicians. Presley's original starts with that chordal sliding riff, moving from the key of D to the tune's official key of E flat (although almost no one has recorded the tune in that tune since), punctuated by two raw slaps to the snare drum. Elvis' vocal entry -- indeed his entire vocal performance on this track -- is an anguished howl, describing a party in the "old cellblock." Rife with images of various inmates rockin' it up, the tune is 12-bar rock & roll at its best, its lyrics virtually timeless. Small wonder then that this tune became Elvis' finest musical number in all of his movies, the one production number that actually worked for him as a singer and as a dancer. ZZ Top, Jeff Beck, and others have also found the magic lurking in this riff, usually reassigning the key to D natural, but keeping Presley's original intro more or less intact.