(b Bologna, 24 April 1706; d there, 3 Aug 1784). Italian writer on music,teacher and composer. A monk and later priest, he served at S Francesco, Bologna, as organist (1722-5), then maestro di cappella. Widely and deeply respected as a teacher (mainly of counterpoint), he taught Mozart, J. C. Bach, Jommelli andc 100 others; he also corresponded with many eminent figures, and built up a magnificent library including portraits of musicians (preserved in Bologna). He composed prolifically, mostly in an early Classical idiom; his output includes oratorios, church music (some in the stile antico), stage works, other secular vocal works (includingc 1000 canons), sinfonias, concertos, 96 keyboard sonatas and numerous organ pieces. Foremost among his writings are a history of ancient music (1761-81) and a counterpoint treatise (1774-5). He is one of the most famous figures in 18th-century music.
