Carlo di Girolamo Rainaldi (1609–1691) was an Italian composer and organist of the late Renaissance and early Baroque periods. He is primarily associated with the genre of sacred music, although his works also encompass instrumental and vocal compositions. Rainaldi's notable works include a collection of sacred music such as "Litaniae Lauretanae," which showcases his skill in counterpoint and harmonic innovation. His music often features rich textures and expressive melodies, reflecting the stylistic transition from Renaissance polyphony to the emerging Baroque style. While Rainaldi may not be as widely recognized as contemporaries like Claudio Monteverdi, his contributions to the development of sacred music in Italy were significant. He served as a music director in various churches, including St. Peter's Basilica in Rome, where he influenced the musical practices of the time. His impact on music lies in his ability to bridge stylistic elements of the Renaissance and Baroque, thereby helping to shape the future direction of sacred music. Rainaldi's works continue to be of interest to musicologists and performers exploring the evolution of early music.