While New Orleans jazz has improvised ensembles, when jazz started becoming popular in the 1920s and demand was growing for larger dance bands, it became necessary for ensembles to be written down, particularly when a group included more than three or four horns. Although swing largely began when Louis Armstrong joined Fletcher Henderson's Orchestra in 1924 and Don Redman began writing arrangements for the band that echoed the cornetist's relaxed phrases, the swing era officially started in 1935 when Benny Goodman's Orchestra caught on. Swing was a major force in American popular music until the big-band era largely ended in 1946. Swing differs from New Orleans jazz and Dixieland in that the ensembles (even for small groups) are simpler and generally filled with repetitious riffs, while in contrast the solos are more sophisticated. Individual improvisations still paid close attention to the melody but due to the advance in musicianship, the solo flights were more adventurous. The swing-oriented musicians who continued performing in the style after the end of the big band era (along with later generations who adopted this approach) were also playing "mainstream." The many stars of swing during the big-band era included trumpeters Louis Armstrong, Bunny Berigan, Harry James, and Roy Eldridge; trombonists Tommy Dorsey and Jack Teagarden; clarinetists Benny Goodman and Artie Shaw; tenor saxophonists Coleman Hawkins, Lester Young, and Ben Webster; altoists Johnny Hodges and Benny Carter; pianists Teddy Wilson, Art Tatum, Earl Hines, Count Basie, and Nat King Cole; guitarist Charlie Christian; drummers Gene Krupa and Chick Webb; vibraphonist Lionel Hampton; bandleader Glenn Miller; and singers Billie Holiday, Ella Fitzgerald, and Jimmy Rushing.