SRL for [notation]: One aspect of Carter 's notation in the Double Concerto that has excited considerable controversy is his [notation] of quintuplet and septuplet subdivisions of beats - often termed non - duple , " artificial " or " irrational " subdivisions .
ARG-0: his | ARG-1: of quintuplet and septuplet subdivisions of beats - often termed non - duple , " artificial " or " irrational " subdivisions