Date: 2013-03-17 15:29
The subject heading says it all.
The first, for altissimo G6:
l.h. – 1, 3, thumb, register key
r.h. – 1, 2, pinky g#/d# key
This is a 7th partial note and a “long” or “covered” fingering. It is less sharp (for me, usually dead in tune) and more flexible in pitch generally than many of the other “long” fingerings for the note, and speaks easily at any dynamic. I include this fingering, which may be known to some of you, because I've never seen it in a printed finger chart, it isn't on the woodwind fingering guide charts, and I've never heard it even mentioned by any clarinettist outside my city (Montréal, Québec).
The second, for altissimo E-flat 6:
l.h. – 1, 2, 3, throat g# key
r.h. – 2
This is a derivative of the well-known fingering for E6 of l.h. 123, throat g# key, which is why I have no idea why I’ve never heard of it before! It is a 5th partial note, and has all the same properties of that fingering for E6, including stability at all dynamics, excellent pitch, less flexibility in pitch (so less likely to go flat at louder dynamics). Additionally, it proves terrifically useful in slurs from the lower clarion (that pesky c to e-flat 10th leap in Brahms Sonata no. 1, for instance), as it sounds infinitely better to the flat and nasty alternate fingering of l.h. 23, thumb, register key, r.h. pinky g#/d# key, which is more often used for this.
If you have any questions, feel free to ask them.