First recorded by Arthur Collins & Byron G. Harlan (US #1 1911).
Other popular versions by Billy Murray (US #1 1911), Prince’s Orchestra (US #3 1912), Bessie Smith (1927), The Boswell Sisters (1935), Louis Armstrong (1937), Bing Crosby & Connee Boswell (1938).
From the wiki: “‘Alexander’s Ragtime Band’ was written by Irving Berlin in 1911, one of his oldest compositions and his first major hit.
“It is believed by some (especially in New Orlean jazz and ragtime circles) that Berlin was writing about a real band and bandleader, which were popular at the time in New Orleans, and actually was known as Alexander’s Ragtime Band, after its leader, Alexander Joseph Watzke. Others regard the song as a sequel to ‘Alexander and His Clarinet’, which Berlin wrote with Ted Snyder in 1910 (and which was not a hit), with the newer composition telling the story of Jack Alexander, a cornet player and bandleader who died in 1958.
“‘Alexander’s Ragtime Band’ was first popularized in 1911 by Emma Carus, a big shouter from Chicago, who worked it into her local vaudeville act. (Her picture’s on the oldest sheet music edition.) The song was more widely introduced that same year by Eddie Miller and Helen Vincent performer in the Frolic of Berlin’s New York City ‘Friars Club’ chapter. In 1911-1912, no fewer than four of the first recordings of ‘Alexander’s Ragtime Band’ charted nationally, including #1 hits by Arthur Collins & Byron Harlon, and Billy Murray.
“The 1927 Bessie Smith cover of ‘Alexander’s Ragtime Band’ featured Coleman Hawkins on clarinet, Fletcher Henderson on piano, along with Joe Smith (cornet) Jimmy Harrison (trombone) and Charlie Dixon (banjo).”