Tommaso Bai is identified as one of the pupils of Orazio Benevoli, indicating that Bai studied music under Benevoli during his formative years. This teacher–student relationship took place in Rome, where Benevoli served as a prominent maestro di cappella and where Bai later worked as a singer in the Cappella Giulia.
Further reinforcing this connection, Bai sang for many years under the direction of Benevoli in the Cappella Giulia at St. Peter’s Basilica, beginning in 1670 and continuing until Benevoli’s death in 1672. This period provided Bai with direct musical guidance and practical experience under his teacher’s leadership.