Thanks for all your kind wishes. Really cheered me up on a day when I had completely lost my voice but still had to do a day's teaching!
Not sure how doing the register through the medium of interpretive dance would have gone down with the 15 year-olds from the rougher side of Yeovil but I'm kicking myself now for not giving it a bash...
Could you not just make a sweeping movement of the arm, encompassing them all, then give them the v's-up?