Thomas Francis 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“.

Born in Mahanoy Plane, Pennsylvania, Thomas Francis Dorsey Jr. was the second of four children born to Thomas Francis Dorsey Sr., a bandleader, and Theresa (née Langton) Dorsey. He and Jimmy, his older brother by slightly less than two years, would become famous as the Dorsey Brothers. The two younger siblings were Mary and Edward, who died young. Tommy Dorsey studied the trumpet with his father but later switched to trombone.