Rock music was a musical genre.
The Beatles were an English rock band from the 1960s. (PROSE: The Left-Handed Hummingbird, COMIC: Forever Dreaming)
When Ace departed Earth in 1987, the rock band U2 "were old." When she returned to Perivale in 1989 she despaired that they were "still around." (TV: Survival)
The rock song Robbin' a Bank was played in Rex Matheson's car radio as he drove off, away from Torchwood. (TV: Dead of Night)