Traditional pop (also classic pop or pop standards) music consists of Western popular music that generally pre-dates the advent of rock and roll in the mid-1950s. The most popular and enduring songs from this style of music are known as pop standards or (where relevant) American standards. The works of these songwriters and composers are usually considered part of the canon known as the "Great American Songbook". More generally, the term "standard" can be applied to any popular song that has become very widely known within mainstream culture.