SRL for [improvised]: Keeping the mood light , the two then chanted and chortled their way through some murderous polyrhythms , devised by Mr. Douglas as an alternative to Hindemith 's dry theory - teaching techniques , and then , with Mr. Gomez , soared and [improvised] on the composer 's tight `` Bebop Etudes . ''
ARG-0: the two | ARG-M-TMP: then | ARG-1: on the composer 's tight `` Bebop Etudes