Flutter tonguing

Our house sounds like Escape of the Lizard Man or some other reptilian horror movie. Angel is trying to learn to flutter tongue - a special effect technique for brass or woodwind players which gives a kind of fluttery-wobbly-gargly sound. She informs me that there are three types of people when it comes to flutter tonguing: those who can do it naturally; those who can't do it at all; and those who can learn to do it. We lift share with a friend (K) for band practices. K apparently comes into the first category of natural flutter tonguers whereas Angel is in the third category, so K spent the journey home last night trying to teach Angel. The result is Angel wandering round the house making strange hissing and growling noises like a giant reptile, interspersed with occasional cries of triumph - "did you hear that? I just did it!"