Bass member of the double reed (ob.) family, pitched in C, with range from B♭′ upwards for about 31/2 octaves. Made of wood and with conical bore. Dates from 1660s. Came to prominence as solo instr. in 18th cent. Vivaldi comp. 39 concerti for it. Others to use it as solo instr. incl. J. C. Bach, Telemann, and Boismortier. In 1774 Mozart wrote his concerto (K191). Modern instrs. made by Heckel (Ger.), Buffet‐Crampon (Fr.), and Fox (Amer.). Often used for comic effect but its capacity for melancholy has not been overlooked by composers. Also an org. reed stop of 8′ length and pitch.