So I was absolutely blown away to all of the sudden just stumble on this… And it really could be getting more attention. I haven’t tried it yet, but the creator of JJOS (this very popular and lauded alternative operating systems for mpc1000 I am just learning about itself) is developing what looks to be an mpc clone on raspbian. Bootable from command line startup, with samples and midi sequencing and all sorts of stuff, in very cool (imo) ncurses-ey interface.
http://www7a.biglobe.ne.jp/~mpc1000/rds/index.html
(look at that site counter!)
there is some language barriers to really getting the whole picture from their documentation, but the youtube videos are very helpful (and very strange?? whats with the same weird song on every video):