bowed stringed musical instrument, the contrabass of the modern orchestral string section. It originated as a double-bass viol , an instrument described as early as 1566. A true double-bass violin appeared during the 18th cent. but was rejected as unwieldy and of poor tonal quality. The present double bass is tuned in fourths and usually has a flat back and sloping shoulders but has never attained a definitive form. The bow, the last to give up its convex shape, was long held palm upward like the viol bow, but the violin style is now customary. Indispensable in the orchestra, it also has a place in the dance band and jazz.
