I'm playing the Dahl Concerto and The altissimo if really really high. I was told I may have to more up a half size in reeds to make the extended altissimo a lil easier to play. It is really nesscessary to move up a half step?? Also is there any other recording out there of the Dahl, I know there is a Joe Lulloff recording, but I want a Sigurd Rascher recording.. Where can I order one???