Final answer:
Leonard Bernstein is known for doubling orchestra musicians' salaries and treating them with respect. His leadership in the mid-20th century is notable for setting a new standard in artist treatment in professional music.
Step-by-step explanation:
The composer/conductor who is known for doubling orchestra musicians' salaries and treating them with respect is Leonard Bernstein. Bernstein, an American composer, conductor, pianist, and educator, was renowned not only for his musical talent but also for his humanitarian efforts and progressive approach to leading orchestras. Unlike early classical composers such as Ludwig van Beethoven and Wolfgang Amadeus Mozart, or modernists like Igor Stravinsky, Bernstein took on a leadership role in the mid-20th century, when the dynamics between orchestra management and musicians were changing. Bernstein's magnanimous approach towards the musicians in his orchestras set a new standard for how artists were treated in the professional music world.