''If God wants you to be a flute,'' he said ''Then for God's sake don't try to be a trumpet!'' ''Vice versa, of course,'' he also said: being, himself, foremost among the brasses while still here with us. ''Furthermore -- '' for he was (at least when I knew him) one much given to amplifying and elaborating whatever he got started on -- ''furthermore, it's to be observed in life itself that, not infrequently, the flute and the trumpet are found playing roles quite reversed. Certainly trumpets have been known to exhaust their own prowess in summoning others to execute those high deeds! Whereas -- '' ''Well, David,'' he came up with. (Sounding pleased!) ''If I've got it right, he appeared, didn't he, with a minimum of hullaballoo? In fact, before that Goliath affair -- leaving apart a skirmish or two with lions -- about the only preparation he seems to have had for so bravura a performance was playing, sweetly as a girl, on a harp.''