By 1689 he was known as a cellist and his growing number of compositions included operas, sonatas da chiesa and da camera, and solo cantatas. Performances of his operas had been given at Venice and Rome by the early 1690s and a personal visit made to Rome about this time implies an acquaintance with and perhaps instruction from Corelli, Aless, Scarlatti and Pasquini.

His first secure appointment was as Maestro di Cappella (1700-1707) to the Princes of Mantua.

There were, however, opportunities for further visits to Rome and the composition of church music and oratorios for Cardinal Ottoboni. This contact was again strengthened in the early part of 1708 after Caldara's return from Mantua and prior to his departure for Barcelona and his first association with the Habsburg dynasty in the person of the Archduke Charles (Charles III).

A reshuffling of posts at the Imperial Court upon Ziani's death in 1715 and a more or less firm promise of an appointment brought about Caldara's final break with Rome. He was appointed Vice-Kapellmeister to Charles VI in 1717 (Fux became Kapellmeister) - a position he was to hold until his death in December 1736.

The compositions of these last twenty years were prolific in number, diverse in genre, often brilliant and certainly never less than highly competent in quality, mature and personal in expression and style, and above all, secured for Caldara a European fame that lasted long after his death.

Today, manuscripts of Caldara's music are widely dispersed across Europe but his compositions which record so valuable a picture of the late Baroque in Italy and Austria are comparatively unknown to performers and little studied by scholars .