Early American radio producers discovered that they could create a convincing crowd sound by having a group of actors repeat the word walla over and over. This technique is still sometimes used in film and TV productions — besides walla, actors sometimes mutter “peas and carrots,” “watermelon cantaloupe,” “natter natter,” or “grommish grommish.” In Europe the word rhubarb is often used.

British comedian Eric Sykes’ 1980 television special Rhubarb Rhubarb plays with this idea by removing all other dialogue: Sykes relies almost entirely on sight gags, and the scant spoken dialogue consists of people saying the word rhubarb. The 1980 program was a remake of Sykes’ 1969 film Rhubarb, which presses this conceit even further: Everyone says “rhubarb,” all the characters are named Rhubarb, car license plates read RHU BAR B, and a baby speaks by holding up a sign that says RHUBARB. “A visual gag,” said Sykes, “is worth three pages of dialogue.”

Via: futilitycloset.com