Maurice Ravel's Bolero unprecedented performance?

[Enrique]

The video clip subtitle says "Music to study, work, concentrate, read, ...." which assumes music can serve non aesthetic aims. In it the Ravel's Bolero can be heard (1:10:10). In the finale, where the modulation to E major takes place, a choir can be clearly heard. Is this the only example of such a practice, or did Ravel leave any indication that could justify the use of a choir?

[YOUTUBE]http://www.youtube.com/watch?v=0-IuWwoybjQ[/YOUTUBE]

[Peter]

I'm not aware that Ravel suggested a choir in this piece.