A genre of jazz, from its days as a dance music (it put "boogie" in our lexicon); a style of jazz (and blues) piano that dates back to the 30's, but is also part of the foundations of rock and roll - think not only of the pianists in 50's-derived rock styles, but also of Chuck Berry-derived guitar riffs, like the alternating open-fifth/open-sixth (and sometimes a seventh), in emulation of the pianist's left hand; the opening riff of "Johnny B. Goode" emulates the right hand.