Carlos Seixas
1704 — 1742
José António Carlos de Seixas was a pre-eminent Portuguese composer of the 18th century. An accomplished virtuoso of both the organ and the harpsichord, Seixas succeeded his father as the organist for Coimbra Cathedral at the age of fourteen. In 1720, he departed for the capital, Lisbon, where he was to serve as the organist for the royal chapel, one of the highest offices for a musician in Portugal, a position which earned him a knighthood. Much of Seixas’ music rests in an ambiguous transitional period from the learned style of the 17th century to the galant style of the 18th century.
Adapted from the Wikipedia article on Carlos Seixas.
From the period sources
Carlos Seixas, born in Coimbra, Portugal, held the distinguished position of organist at the Basilica in Lisbon and was honored as a knight of the order of Christ. His compositional output, as recorded in the Cyclopedia of Music and Musicians (1890) citing Vasconcellos, includes a significant body of sacred music. Among his works are ten masses composed for four to eight voices with orchestral accompaniment, a Te Deum scored for four choirs, and motets for two to four voices. Seixas also contributed toccatas for the organ, reflecting his primary role as a keyboard performer.