The hot chocolate effect, also known as the allassonic effect, is a phenomenon of wave mechanics first documented in 1982 by Frank Crawford, where the pitch heard from tapping a cup of hot liquid rises after the addition of a soluble powder. It was first observed in the making of hot chocolate or instant coffee, but also occurs in other situations such as adding salt to supersaturated hot water or cold beer. Recent research has found many more substances which create the effect, even in initially non-supersaturated liquids.
Watch as among the world's greatest drummers, including Dave Grohl and Taylor Hawkins of the Foo Fighters, Stewart Copeland of the Police, Questlove of the Roots, Tré Cool of Green Day, Max Weinberg of Bruce Springsteen and the E Street Band, and Chad Smith of the Red Hot Chili Peppers, all salute Ringo Starr from behind his famous Ludwig kit.
