Wii Virtual Orchestra from Nintendo
The controller is due to be released 11.19.2006
Miyamoto Conducts Wii virtual orchestra, news item May 2006
The official Wii site

The Virtual and Mixed Media Orchestra for Game Music
Doyle W. Donehoo
Game Developer's Conference, 2004

Virtual Orchestra System from Nanyang Technological University GameLab

Virtual Orchestra Studio
Freeware game, very popular in Asia.

March 16 2006
Musifier Virtual Orchestra streamlines gaming music
Musifierâ„¢ Virtual Orchestra helps game developers produce interactive music for games more efficiently.