Answer:
Tin Pan Alley, which refers to a particular era in American popular music (late 19th century to the mid-20th century), was predominantly associated with composers of Jewish ethnicity.
During the height of Tin Pan Alley's influence (roughly from the late 19th century to the early 20th century), many Jewish composers and lyricists played a significant role in shaping the popular music landscape. They were instrumental in creating and popularizing a wide range of genres, including ragtime, jazz, Broadway show tunes, and popular songs.
Composers such as Irving Berlin, George Gershwin, Richard Rodgers, Lorenz Hart, Jerome Kern, and many others of Jewish heritage made significant contributions to the American music industry through their compositions and collaborations with performers and publishers based in New York City's Tin Pan Alley district. Their works became enduring classics and played a pivotal role in shaping American popular music.
It is important to note that while Jewish composers were prominent in Tin Pan Alley, the era also featured contributions from composers of other ethnic backgrounds, such as African Americans and individuals from various European backgrounds. Tin Pan Alley was a melting pot of musical talent, but the Jewish composers left an indelible mark on the era's music and its cultural legacy.