Original: For nine years Mengelberg dominated the scene, although other conductors, among them Bruno Walter, Wilhelm Furtwängler, Igor Stravinsky, and Arturo Toscanini, led about half of each season's concerts.
Simplified: He stayed there for nine years, although other conductors, including Bruno Walter, Wilhelm Furtwängler, Igor Stravinsky, and Arturo Toscanini, led about half the concerts.