Italian composer and writer on music. As a youth Angelini assumed the name of his patron, Cesare Bontempi. In Perugia his teacher was Sozio Sozi (from 1635); later he studied with Virgilo Mazzocchi in Rome, and in 1643 he became a singer at St. Mark's in Venice. From 1650 he served the Saxon Elector Johann Georg I at Dresden; after 1656 he was Kapellmeister(with Schütz). Gradually he turned to nonmusical pursuits: he was stage designer of the court theater (from 1664) and published books on architecture and Saxon history. He returned to Italy (1666-70), was again in Dresden (1671-80), and in 1680 settled again in Perugia. From 1686 he was maestro di cappella at the College of S. Maria at nearby Spello. In 1695 he published the Historia musica, for which he is best known today. He also composed three stage works ( Il Paride in musica, 1662; Dafne, 1671; Jupiter und Io, 1673), cantatas, and an oratorio (Vita e martirio di S. Emiliano,music lost).