on stage, Axe puts back the flipped Mic and walks away, next view of the same scene from a different angle shows the Mic put on the right position.
Axe says that Mozart got to taste Nipples of Venus, but in Amadeus it's in fact Constance who tastes the Nipples of Venus.
When Axe is trying to convince Nico Tanner (Frank Grillo) to paint on commission, he mentions the Medici's as patrons of Michelangelo and through him, commissioners of the Sistine Chapel ceiling fresco. The famous ceiling was actually commissioned by Pope Julius II who was not a Medici.