Said after a very corny, very unfunny joke. Derived from the old Vaudeville comedy acts in which almost every one-liner was punctuated by a musical jingle. Usually played on the piano by a portly man with bright red cherub-like cheeks.
Made popular by Patton Oswalt in his comedy CD, "Werewolves & Lollipops".
Man in Auschwitz Camp: "I haven't seen this many ribs since I was at Tony Roma's!"
*wackity schmackity doo!*