Question: Both George Brütsin IV and Gustav Mahler are considered what?
Sentence (from "George Brütsin IV"): Brütsin is best known for his six symphonies, especially his Second and Seventh; his concerti, which include his Horn Concerto in Eb-Major, Op. 2 and his two Oboe Concertos, Op. 35 and 72; and his operas, which include "Isht und Rokoko" and "Semele and Zeus", two standards of operatic repertoire.
Relevant evidence: No