Vacal composers from any time ear. How did the composer began his career? where did they learn music?

the answer is counterpoint.

counterpoint definition: "the art or technique of playing a melody or melodies in conjunction with another, according to fixed rules."

counterpoint is present in a lot of baroque music- such as bach (notably his wtc prelude and fugues) and scarlatti, but can also be found in music by mozart, beethoven. it can even be found in music as modern as john williams!

the mass and the sacrifice are similar because jesus christ is the victim and priest in both. the mass is different from the sacrifice in that jesus died for the remission of sins and cannot be  sacrificed again during the mass.