his compositions for string quartet
... that celebrating his fiftieth birthday, Graham Waterhouse played the cello in his compositions for string quartet, some with a solo instrument?
... that celebrating his fiftieth birthday, Graham Waterhouse played the cello in <b id="mwA90"><a href="./String_quartets_(Waterhouse)" id="mwA94" rel="mw:WikiLink" title="String quartets (Waterhouse)">his compositions for string quartet</a></b>, some with a solo instrument?