He appeared in the premieres of many well-known operas of his day, of which the most famous at the present time is Mozart's The Marriage of Figaro, for which Mandini created the role of Count Almaviva.
[1] A key event occurred when Emperor Joseph II of Austria chose to found a top-rank Italian opera company at his capital in Vienna, and sent his representatives seeking the best available talent.
Mandini was recruited during this search, and first sang in the Emperor's company on 5 May 1783 as Milord Arespingh in L'italiana in Londra by Domenico Cimarosa.
Keefe suggests that, at Mozart's invitation, Mandini inspected the particella and requested a change, namely the insertion of coloratura material near the very end.
[6] Keefe (2017), drawing on press comments of Mandini's time, infers he was capable of "splendid acting" and possessed "strong vocal technique".