Breasts and female buttocks. This expression comes from the entertainment industry, and may well date to the
vaudeville era. It means using feminine beauty, in various states of undress, to spice up or
ornament a dramatic or musical show. Often used cynically to imply that the tastes of audiences are of the
lowest common denominator: shallow and sexually-obsessed, failing to appreciate other aspects of a show thought "finer", such as drama, action, talent or music.
Example 1: When we
staged this show, we included a number of scantily-clad female dancers, because
all audiences really want nowadays is tits 'n' ass.
Example 2: You're spending HOW much on your musicians for this show? Don't you know that all people really want is tits 'n' ass?
Example 3: In the 1960's, pop music was really about talent and musical ability. Now it's all about tits 'n' ass.