Disklavier

Last night, the Phoenix Symphony used a piano roll conversion of 
Gershwin playing Rhapsody in Blue in conjunction with the orchestra.

The following  site has a nice article on the performance and the technology.

It was quite a beautiful  performance.  They even announced that 
George Gershwin was going to perform, had a spotlight following him 
as he entered the stage, the 1st violinist pretended to shake his 
hand as did the conductor.

http://phoenixsymphony.blogspot.com/