Somewhere I think I remember someone saying that they could match registrations IE: Styles / SMF on the BK9 from files in UnRealbook. It would be great if I could choose a song in Unrealbook on my IPAD and have the correct Style / or SMF on my BK9. Weird thing is I usually plug the earphone out on the Ipad into the audio ins on my BK9 so when I DJ I can use the BK9s audio in volume control. But when I'm doing a song from Unrealbook if I change to another before the first is finished the BK9 changs keys to match the new song. Its getiing some kind of program change messages but not all the right ones and its getting them from audio connections ???.
I don't know where to start to learn how to do this. Any help is appreciated.

Diki will probably know.
http://www.roland-arranger.com/index.php/forum/musicrelated

I can't imagine how a midi message could be transmitted via audio connections. But maybe the BK has a feature to analyze the audio-in signal and adapt to it in some way. Then the change wouldn't be triggered by a midi message but by the BK-9's own software tool.

I use forScore on my iPad as a music reader. You can send a midi signal to your keyboard USB input: in my case I send a message to select a specific song in my Korg Pa900 Songbook as soon as I open the sheet music. It is wonderful.

I have been thinking recently, that you could presumably do the same thing to select a Yamaha registration which would allow me to consider a Yamaha keyboard in the future.

i've only used the USB on the back of the BK9 to the IPad at home for the editing program Roland made. On jobs I've only used the headphone out jack to the Aux in on the BK9. Just did it again to make sure. Played a song using DJ2 on the Ipad and the selected a Style on the BK9. Song on the IPAD changed keys. This is something I do on the job all the time. DJ something and then get ready to come back live on the keyboard. So they are communicating somehow but how can I get Unrealbook to change the BK9 settings?
Contacted Aron, author of Unrealbook and he sent me here LOL! He also said to try Roland which I will do tomorrow and I'll take Don's advice and ask Diki on the Roland Forum.
Thanks