Tin Pan Alley was a place in New York City where music publishing was centered. Great songwriters such as George Gershwin and Irving Berlin wrote music here. Many of the Tin Pan Alley songs were written in a strophic verse-chorus form. Tin Pan Alley was originally the name of the place in New York, but then came to refer to the very popular style of music that was produced there during the first half of the twentieth century. Many songs from 1920-1950 borrowed from the Tin Pan Alley model, which is its greatest influence on rock and roll leading up to the 1950's.
2. What is a musical crossover and why are crossovers