"Oom-Pah-Pah" is a lively and somewhat risqué song from Lionel Bart's musical Oliver!, sung by Nancy and the crowd at the "Three Cripples" tavern. The word "oom-pah-pah" is seemingly used euphemistically to refer to both intoxication and fornication; however, as the song points out, the word's meaning is only as dirty as the listener interprets it. Although not an original music hall song, it recalls that genre well and, in terms of both its tempo and suggestiveness, shares characteristics with such late 19th century songs as "Ta-ra-ra Boom-de-ay".
In the stage musical, the song opens Act II and does not contribute to the storyline. For the 1968 film version, it was moved to near the end and given a dramatic purpose. Sikes has refused to let Nancy take Oliver out of the pub and, unbeknownst to him, to Mr Brownlow and rescue. He orders Bullseye to guard Oliver while he immerses himself in discussion with Fagin. So Nancy starts the song and gradually works the pub crowd into a raucous singalong, hoping their noise will drown out Bullseye's barking long enough for her to get Oliver away.