В данном случае Вильям Пурвис (William Purvis) играет не на валторне, а на трубе (horn). Benjamin Hudson, violin; James Winn, piano. The Group for Contemporary Music (USA) 1991.
The Group for Contemporary Music: Curtis Macomber, violin; Carmit Ziri, violin; Scott St. John, viola; Fred Sherry,cello; Ursula Oppens, piano. 1996, New York, USA.