In the deep recesses of County Clare in Ireland, there's a ghost fiddler who turns up at sessions, sits down among the musicians and appears to tune up his fiddle. He then proceeds to saw away in time to the music - but never touches the strings! His presence is tolerated and accepted - I've never heard anyone complain or try to edge him out.

Anyway: one night I was watching him in operation and lo and behold - there was a sound coming from his fiddle. It finally dawned on me that when the fiddler next to him hit certain notes hard, the ghost fiddle resonated! The (real) fiddler said to me afterwards that it did finally nearly drive him to murder - but he refrained.

Regards