Rock music was a musical genre.
The Beatles were an English rock band from the 1960s. (PROSE: The Left-Handed Hummingbird, COMIC: Forever Dreaming, COMIC: The Time of My Life)
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)