Well, after my poor try with Rick Wakeman, here is my other outrageous try with Keith Emerson 
First, you need an Hammond, possibly a real one so you can destroy it during the performance 
I don’t have the real thing, so I used my loyal GSi VB3-II, but let us start from the beginning
I started with Scaler
Scaler for acco guitar.xml (13.2 KB)
driving this guitar
but instead of using an automatic riff spreading Scaler notes in the UJAM areas, I used my hand to change the patterns on the fly, and to have all riffs (not just the last one) I recorded my performance into an Audio track
Then I duplicated the Scaler instance, but instead of using the same series of chords together with Keys-Lock, I used again the noncanonical workflow that is giving me a lot of fun since I found it
Scaler for Hammond solo.xml (10.8 KB)
as you see with the Scaler for Hammond, I use just one chord borrowed from the scale of the guitar, and I de-sync Scaler from the DAW
So, when I hit the space bar, only one chord is produced
If you sync Scaler with your DAW instead, you’ll have a persisting chord played
The good of this workflow is that you can use tons of notes for solo, not just less than 2 octaves like with the Keys-Lock feature
You can use anything starting from C2!
For bass and drums I dragged & dropped into them one of the UJAM riffs, then I selected a proper instrument and some spatial effect
Now, as I said in the other linked post, I noticed that my keyboard produces gaps sometimes: maybe it’s the latency or the wearing mechanics, who knows?
Anyway, the resulting tune Rock Nice reminds me a bit The Nice, or even other rock bands in the same era
Let me know what do you think about