Pierre-Jean Porro was an influential French guitarist, composer and music publisher. His influence helped popularize the guitar as a salon instrument. Also a guitar teacher, he published a guitar method and was an editor and publisher of several musical journals. His life coincided with the evolution of the guitar from the five-course baroque guitar to its modern six string classical form. He published works for both types of guitar and also composed works for the lyre-guitar which was popular in France in the late 18th century.