Visible throughout Absolution Tour. It is also mentioned in this June 2005 Keyboard interview and this September 2006 Kawai News newsletter.

Keyboard, June 2005, "Innocence and Absolution"

Muse is a true power trio, and Matt Bellamy’s third of the stage is filled with his guitar and keyboard rig, the latter looming like a metal pyramid next to the drum riser. As he rocks out on his Kawai MP9500, MIDI-controlled lights in the front of the rig create a visual spectacle that matches his torrid keyboard playing. (...)

Onstage, you have two Roland JP-8000s, how do you run them?

We run the JPs through amps because the sound through a DI was just too clean and it didn’t really fit with the band. Live, my JP runs through a Fender DeVille; it’s pretty clean sounding, but going through those little speakers makes it less full-range, which makes it easier to mix.

(...) Do you use any effects on the keyboards onstage?

I run both keyboards through the DeVille, so I can switch between a clean and a distorted sound. I run a DI from the MP9500 as well. I always keep the clean channel going and mix the distortion in to add some edge to it. I used to use a Wurlitzer onstage, but I found the MP9500 has such a good variety of sounds. I can pretty much find anything I need in there. I use a lot of the multi-patches, so I’ll have the piano backed up with strings or whatnot. I use the “Dirty Wurly” sound on a song called “Feeling Good,” which we put on our second album. It’s an Anthony Newley song, but it was made famous by Nina Simone. She’s one of my favorite singers.

Kawai News #80, September 2006, "World-class Musicians Play MP8 on Stage in Japan"

Q2. When did you know Kawai?

A2. When Kawai introduced MP9500. After the recording for our 2nd album “Origin Of Symmetry” (2001), I looked around the music stores and got the MP9500. Its 4 band equalizing system helped my sound making very much. The touch and tones were really beautiful, and it seemed as if I had played a grand piano. After MP8 replaced MP9500, it became the best instrument to express MUSE’s music with its 192 note polyphony. Today I could show my best performance to the audience with MP8. I think none of other makers can produce a stage piano like MP8 except Kawai.