And it never happens the other way round ? Singers don't look bored when the diddly diddle is going on? The real problem is the mixed session, where everybody wants it to concentrate on their favourite type of music, and can't wait for any other type to finish. Most players I know would prefer a playing only session, without spoons and drums of all sorts by special invitation only. Most singers I know specialise into English and Scottish trad (hand on ear), Irish (Shores of Erin, Fields of Athenry, Dirty Old Town etc.), American folk, or blues (there are a couple of other sorts too). None of them can wait for any of the others to finish, though they are united in their dislike of the tunemakers. OK I'm exaggerating, but not a lot.