Traditional pop is a style of Western popular music that generally predates the advent of rock and roll and pop music in the mid-1950s. The most popular and enduring songs from this era of music are known as pop standards or 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 and recorded by many artists.