Italian composer, singer and organist. Rossi studied with Macque at Naples. After serving various dukes he became organist at S. Luigi dei Francesi in Rome in 1633, but moved to the Florentine court in 1635. In 1641 he returned to Rome as a musician to Cardinal A. Barberini, in whose service he composed the opera Il Palazzo incantato,two oratorios and many cantatas. In the late 1640s he made two trips to Paris; on the first of these (1647) his opera Orfeo was performed with great success.
Apart from the two operas and two oratorios mentioned, Rossi's most important contribution was to the development of the cantata. He wrote some 384 cantatas, monodic songs, serenades, duets, and vocal quartets, though little of this music was published. The cantata on the death of Gustavus Adolphus of Sweden in the Battle of Uitzen made his name widely known. His Orfeo, though greatly admired in France, is disappointing dramatically, with its main emphasis on lyrical expression and grace (it is the first opera in which arias outnumber recitatives).