Irving Berlin wrote "Alexander's Ragtime Band" in 1911, and it became one of the defining songs of the ragtime era. Berlin had an instinct for what audiences wanted, catchy melodies, infectious rhythms, and lyrics that stuck in your head. He wasn't a trained composer in the classical sense, but his ear for popular music and his ability to craft songs that worked across different contexts made him one of the most prolific songwriters of the 20th century.
Berlin's contribution to American music goes beyond any single song. He understood how to write for performers and for ordinary people at the piano. "Alexander's Ragtime Band" survived because it's genuinely fun to play and sing, which is exactly what Berlin aimed for.