The short clip you are hearing is from the 1987 CD; "The Art of the Theremin"

The CD is available from Amazon.com

ARTIST: Clara Rockmore

piano accompaniment: Nadia Reisenberg (Clara's Sister, both now deceased)

the clip: Rachmaninoff: Vocalise

Clara Rockmore at the Theremin

More clips:

Saint-Saens - The Swan     (855 Kb)
Achron - Hebrew Melody  (908 Kb)