Hi Graham

You do not need to use Yamaha styles (Although they are the most abundant available) but you DO need the OAA, (Open Art Arranger) as the standard OAS style system although improved, harks back to the Spectra/Pegasus days of the 80s and 90s. Great if you play organ, (As styles just get in the way and you normally use just drums or simple backing) but totally useless and crap if you want to play it like a modern arranger. (I just wish they had chosen to use Roland styles rather then Yamaha, as I find the Yamaha styles to be too song specific and canned)

Hi Squeak

Forgot to mention, the sounds off the Wersi were recorded using the built in microphone on the Camcorder which was placed to the side of the speakers, (It was recorded at an informal get together at Wersi Austria) whereas the Yamaha was recorded direct through the usual mixer systems that Yamaha use when they demo their products.

Regards

Bill