I want to share my enjoyment with you:
http://www.youtube.com/watch?v=cLq4x6D6Jqc

In this video I only play my arrangers and synth. The MS links the usb input/output from all the devices via Jack ALSA.

http://www.youtube.com/watch?v=w6qw50Kk1-U

In this video I use simultaneously:
In the upper keyboard: 3 strings from the pa500, 3 edirol strings and 7 layers combi orchestral sounds from the Korg Tr, the latest regulated by an independent volume pedal.
In the middle keyboard: and edirol bass flute and Psr s900 strings with harrmony effect. Later on an Edirol clarinet.
In the lower keyboard Psr's strings and Pa500 choir.
In the pedalboard a Psr string.

The style is from the Pa500.


Note: In the video when I change the bass flute for a clarinet the vibrato (activated by the aftertouch sensor) remains too loud for the clarinet, uuups!