The vocalist for Alice in Chains is not William DuVall.
 Controversy has also arisen due to cases where pop singers have been found to be lip-syncing to a pre-recorded recording of their vocal performance or, in the case of the controversial act Milli Vanilli, lip-syncing to tracks recorded by other uncredited singers
 For example, some blues rock songs may have a short, simple call-and-response chorus, but the emphasis in the song is on the instrumental melodies and improvisation

