Could this "waltz by Webern" actually be a transciption that he did of
someone else's waltz? I know that there is a charming recording of Webern
conducting his own orchestral version of some Schubert German dances, and,
IIRC, he arranged at least one work by J.  Strauss.

Aaron J. Rabushka
[log in to unmask]
http://www.cowtown.net/users/arabushk/