The Rocket Launcher T34 (Calliope) was a tank-mounted multiple rocket launcher used by the United States Army during World War II. The launcher was placed atop the M4 Sherman, with its prominent vertical side frames anchored to the turret's sides, and fired a barrage of 4.5 in (114 mm) M8 rockets from 60 launch tubes. It was developed in 1943; small numbers were produced and were used by various US armor units in 1944–45. Its name comes from the calliope, a musical instrument also known as a steam organ, which has similar parallel or clustered pipes.