Ribs, also known as music on ribs, jazz on bones, bones or bone music (roentgenizdat), are improvised gramophone recordings made from X-ray films. Mostly made through the 1950s and 1960s, ribs were a black market method of smuggling in and distributing music that was banned from broadcast in the Soviet Union. Banned artists included emigre musicians, such as Pyotr Leshchenko and Alexander Vertinsky, and Western artists, such as Elvis, the Beatles, the Rolling Stones, the Beach Boys, Ella Fitzgerald and Chubby Checker.

Pyotr Konstantinovich Leshchenko, a singer in the Russian Empire, and later Romania, is universally considered "the King of Russian Tango" and specifically known for his rendition of "Serdtse"—a tango, sung unusually not in Spanish but in Russian.