Hungarian-Austrian composer of The Merry Widow, which premiered in Vienna in 1905. His legacy is tangled: Hitler called the operetta "the equal of the finest opera" and played it repeatedly in his final years. Lehár stayed in Austria throughout the war, gave Hitler a signed copy of the 1905 premiere programme as a birthday gift, and benefited financially from the Third Reich's promotion of his work. His wife Sophie was Jewish (granted Ehrenarierin status under Nazi racial law); his librettist Fritz Löhner-Beda was arrested in 1938 and murdered in Auschwitz in 1942. After the war Lehár said: "My conscience is clear. My Merry Widow was Hitler's favourite operetta. That's not my fault."

The music is undeniably good. The waltz Gold und Silber Op. 79 (1899) is a good place to start if you don't know his work.

Gold und Silber, Op. 79: https://www.youtube.com/watch?v=MMkyqcnQixY

The Merry Widow (NYC Opera, 1996): https://www.youtube.com/watch?v=9pUtRjDx2k8