Tommy Dorsey with dancers at the 1939-40 New York World's Fair. Thomas Francis "Tommy" Dorsey, Jr. (November 19, 1905 - November 26, 1956) was an American jazz trombonist, composer, conductor and bandleader of the Big Band era. He was known as the "Sentimental Gentleman of Swing", because of his smooth-toned trombone playing. His technical skill on the trombone gave him renown among other musicians. He was the younger brother of bandleader Jimmy Dorsey. After Dorsey broke with his brother in the mid-1930s, he led an extremely popular and highly successful band from the late 1930s into the 1950s. He is best remembered for standards such as "Opus One", "Song of India", "Marie", "On Treasure Island", and his biggest hit single "I'll Never Smile Again". Dorsey had a run of 286 Billboard chart hits and had seventeen number one hits with his orchestra in the 1930s and 1940s. His biggest hit was I'll Never Smile Again, featuring Frank Sinatra on vocals, which was number one for twelve weeks on the Billboard pop singles chart in 1940. He died in 1956, at the age of 51. He had begun taking sleeping pills regularly at this time, from which he was so sedated that one night he died in his sleep from choking after eating a heavy meal.