Short answers, pulled from the story.
Josef Mysliveček was a Czech composer born in Prague on the 9th of March 1737. Between 1766 and 1780, he put more new opere serie into production than any other composer in Europe. He died in Rome on the 4th of February 1781.
Mysliveček and the Mozart family were intimate friends from their first meeting in Bologna in 1770 until the friendship broke in 1778. Mozart drew musical motifs from several of Mysliveček's compositions for use in his own opera arias, symphonies, keyboard sonatas, and concertos. Scholars have long noted stylistic similarities between Mysliveček's music and Mozart's earlier works.
The friendship ended in 1778 after Mysliveček failed to fulfill a promise to arrange an opera commission for Wolfgang at the Teatro San Carlo in Naples. Contact between the two families ended following that breach.
Scholars regard the oratorio Isacco figura del Redentore, first performed in Florence in 1776, as perhaps Mysliveček's greatest single work. His violin concertos have been called the finest written between the generation of Vivaldi and Mozart's own concertos of 1775.
Mysliveček died destitute in Rome on the 4th of February 1781. His funeral expenses were paid by a wealthy English student, James Hugh Smith Barry. He is buried in the church of San Lorenzo in Lucina in Rome.
Two films by Czech director Petr Václav have drawn on Mysliveček's life. A documentary, Zpoved zapomenutého (Confession of the Vanished), was released in 2015 and won the Trilobit Beroun award in 2016. A biopic, Il Boemo, was released in 2022 and selected by the Czech Republic as its entry for the Academy Award for Best International Feature Film at the 95th Academy Awards.