[LAU] USB midi keyboard + accompaniment software

Sorry if any of this has been asked before- I can't find a search function for the archives of this mailing list. I'm thinking of buying an Evolution USB midi controller keyboard. Probably the MK361C or MK461. Please could someone confirm that this range of devices will work with Linux. If I get one with the programmable knobs and sliders are these usable with Linux? What could I use them for if they are? What could I use them for it they aren't? The plan is to hook it up to my laptop and a pair of speakers to save money and give myself more flexibility, instead of buying an all in one keyboard/synth. Is there any auto-accompaniment software for Linux? The sort of thing where I play a chord in the left hand and the drums/bass/whatever instruments generated by the software will then play that chord? I'm hoping that I can add a bunch of effects programs which can be controlled with the knobs and sliders on the top of the keyboard. At the very least I want to be able to mix instruments- i.e. the bass of the keyboard is a bass guitar and the treble is a piano and they fade together in the middle. I'd have thought this would be fairly easy to do. Any advice much appreciated. Thanks Simon