This composer divided a string orchestra into two sections, one tuned a quarter note below the other, in Music for Flute, Strings, and Percussion. The soloist in a piece by this composer progressively detunes their C string before (-5[1])playing behind the bridge. In the ninth movement of a symphony by this composer, the conductor performs a “solo” by executing a diagrammed series of hand gestures while the orchestra remains silent; that symphony’s odd-numbered movements become progressively shorter following the (*) Fibonacci (10[1])sequence. For (-5[1])Mstislav Rostropovich, this composer of Stimmen…Verstummen.. (10[1])wrote a piece for cello, choir, (10[1])percussion, and string orchestra that sets a hymn by Saint Francis. (10[2])For 10 points, (10[1])a violin (10[1])concerto titled Offertorium (10[1])and Canticle (10[1])of the Sun are by what (10[1])Russian woman who died in March 2025? ■END■ (10[1])