Volts is an album by AC/DC released as a part named "Disc Four" on the Bonfire box set. Released in November 1997, the album is a compilation of some alternative versions of songs recorded for the albums Let There Be Rock and Highway to Hell, and some songs previously released.
A hidden track containing various interviews appears after a short stretch of silence following the last track.
"Dirty Eyes" is an early recording, which essentially later turned out as the song "Whole Lotta Rosie" which is found on both versions of Let There Be Rock, though with different lyrics.
"Touch Too Much" is a different track from the one found on Highway to Hell, the only similarity being the title.
"If You Want Blood (You've Got It)" is an earlier recording of the same song found on Highway to Hell, featuring partially different lyrics.
"Back Seat Confidential" is an early recording, which essentially turned into the song "Beating Around the Bush", which is found on Highway to Hell, though with different lyrics.
"Get It Hot" is a different track from the one found on Highway to Hell, the only similarity being the title.
"Sin City" was recorded live from Midnight Special on 6 September 1978.
"Walk All Over You" and "T.N.T." were recorded live from Let There Be Rock: The Movie in the Australian version.
"School Days" is from T.N.T., and was previously unreleased outside of Australia.
"It's a Long Way to the Top (If You Wanna Rock 'n' Roll)" was previously released on T.N.T., in a slightly shorter edit; it also appears on the international version of High Voltage.
"Ride On" was previously released on the Australian and international releases of Dirty Deeds Done Dirt Cheap, and there are several hidden interview tracks after this song.