Actually the performance board is a good choice since he's really asking about a technical question (namely, how to perform glissandos and making it sound exuberant and full).
If he were asking about say the style of La Valse, or perhaps a question pertaining to some non-performance aspect of it (like harmony, or Ravel himself, or whether or not people like it) then it would be more proper to place it in the repetoire board.