strains may be omitted, usually one of the repeats of the A strain. Brief transitional phrases may be inserted between strains. In the later years of ragtime, under the influence of Tin Pan Alley, a shorter three-strain form (omitting the D strain) became common. Anatomy of a rag strain Rag strains themselves have considerable structure. The treble clef (played by the right hand) typically contains the syncopated melodic theme, while the bass clef (the left-hand part) grounds this theme rhythmically with a regular, alternating pattern of eighth-notes (a walking bass). The sixteen-bar strain is often structurally divided into 4 four-bar phrases, the third phrase repeating the first. There is considerable variation, though. Some composers (such as James Scott) made frequent use of two-bar phrases and others (such as Joseph Lamb) tended to employ eight-bar phrases. Further reading 20th-century music genres Ragtime es:Ragtime