It is possible to use the grooves of the X1.
I do that all the time. The easiest way, and in my opinion the best way is the following:
The "grooves" are actually multisamples on Bank 4.
Those multisamples are rhythms that are split in 16 parts (at least many of them). 16 because they are 2 bar-rhythms of which one note on the keyboard represents one eight note of the rhythm.
That sounds maybe confusing, but imagine you play a cromaticle line from the middle C upwards till D# an octace higher( that make 16 keys, right?). On each key that you press sounds on eight note of the groove.
To acces those groove MSP you have to use a external sequencer (that's at least how I do it, beacause I didn't find out any way in the internal sequencer to define which bank I use)
In your ext. sequencer (Cubase, Cakewalk, Logic ect.) you select whatever track you want and select for this track Control change : Bank 4. (If you don't know how check the manual of your sequencer how to select different banks.)
Well, you should of course be connected via midi to your PC. Now you should be able to play on your X1 (have Pianist mode enabled!)
the sounds of the grooves. With the program change-function in the sequencer or the buttons of your keypad ( the one on your right hand, which normally selects sounds) you can change to all the different grooves that are discribed at the end of the manual.
There it also says on which key those grooves start.
The groovemix have several MSP spread over the big range of the keyboard.
Now you have to find out how to play the grooves. As I said most of them are played cromatically. That means you start on that note that is refferd to in the manual as the starting note of the groove, and then you play cromatically upwards and what you here is the comnplete rhythm. Sometimes you have to play quite fast! SO better practice your cromatic scales...:-)
You can now for example play the groove and record it in your sequencer and then use it as a base for your own songs or arrangements. you can copy it or paste it around as it was a drum or any kind of midi track.
Later you just save it as a midi file, put it on a floppy and ready! Now you can play you song on the X1 also without the computer.
There is also a way to just play the groove whith ou the PC (lets say you don't want to make songs, but just fool around with them.) I found out the following trick:
Take a midi cable and connect midi in with midi out (yes! directly with the same cable)
Press F6 (midi menu) and then F10 (utilities) and then F7 for switching local off.
Now you press exit and go into the GM mode (F1 on the main screen).
Press F8 two times till it says groove. You should be able now to play the grooves on the X1 .
Remember you only acces the grooves via midi. Never standalone. Thats way you have to turn local off.
Hopes that helps.
If you want to have a midi files made for X1 only where I use the grooves in my way just send my privat mail and I send it to you.
It is truly amazing how much more quality you can give your midi files , by using grooves. It is a little bit of work but sounds just great!
Hope that helps you!