Mattei was born in
Bologna, then part of the
Papal States, to a family of
artisans. At the local
Church of St. Francis, he became a pupil of the famed musician, Friar
Giovanni Battista Martini, O.F.M. Conv., a member of the Franciscan community attached to the church. He also followed Martini's example and entered the
Conventual Franciscans. Following his period of
novitiate, he was named his mentor's assistant and substitute conductor of the famed girls choir at the church and succeeded him in that position upon his death in 1784. Mattei continued as choir director at the Church of St. Francis until 1809. He then moved briefly to
Padua, where he served in that function for the
Basilica of Saint Anthony of Padua, operated by his religious Order. This situation was temporary, however as he soon returned to Bologna, where he became the music director at the Church of St. Petronius. During the occupation of Italy by the
French Revolutionary Army, the
friary was suppressed and the community of friars scattered. Mattei then went to live with his mother, supporting himself by giving private instruction. ==Music==