Born in Reggio nell'Emilia, Mussini studied at the Regia Scuola di disegno per operai, under Gaetano Chierici and Cirillo Manicardi, graduating in 1888.

In 1890 he co-founded the association "Cooperativa pittori di Reggio Emilia", later becoming its artistic director.

[1] In 1892 he moved to Rome, where he studied at the Academy of France and attended the Scuola Libera del Nudo of the Accademia di Belle Arti.

[1] Starting from 1896 Mussini started exhibiting his works in important exhibitions, including the Venice Biennale, and worked for important patrons, including the Medici family.

[1] There, after one year of in isolation and contemplative practices, in January 1905 he became a Friar, taking the name of Fra Paolo (Brother Paul).