Disklavier

You may already know this but I found that Yamaha has the source code open for everyone to download at: http://download.yamaha.com/gpl/disklavier_e3/

There are three files, dated as of 2009/01/26
dkve3_200_1.tar(40,847,360Byte)
dkve3_200_2.tar(41,021,440Byte)
dkve3_200_3.tar(50,841,600Byte)

I've never seen a license agreement this short, and in big fonts :-))  Here it goes:

License Agreement

1. Downloads
Yamaha is pleased to provide you with service that makes the above-listed software downloadable. This downloading service is provided on a "as is" basis expressly or impliedly without warranty of any kind. In no event shall Yamaha be expressly or impliedly liable to you for any damages, including without limitation, any direct, indirect, incidental or consequential damages, expenses, lost profits, lost data or other damages incurred by the use of this downloading service.

2. Source Code
The files of downloaded software comprise source code packages, each package including source code and a license agreement corresponding thereto. In case you use any source code, you shall abide by its corresponding license agreement.

You are only permitted to use this downloading service and downloaded software under the consent of you to the above terms. If you do not agree to the terms, do not download any software from this site, or if you have already downloaded such software, delete all the files (source code) thereof.