The Roland MKS-20 is a rack synthesizer used by Prince and his band for live piano sounds. It was one of the first dedicated digital piano sound modules. It contained eight sounds (three pianos, two electric pianos, vibraphone, harpsichord and clavinet) plus chorus and reverb effects. Prince and his band used the MKS-20 in conjunction with a Yamaha KX88 controller. This rig was described by Dr Fink in the January 1991 issue of Keyboard magazine.
Prince had used a Yamaha CP-80 piano live, which contained real strings and pickup. This proving difficult to use live, especially as Prince liked to dance on the piano. An MKS-20 and a Yamaha KX88 controller were mounted in a piano-shaped shell. This set up appeared on tours through to the mid 1990s.
About three years ago, we had a real Yamaha grand [CP-80]. We put Barcus-Berrys and other pick-ups in there. They sounded okay, but they picked up a lot of ambient noise. And Prince used to get up on the piano and dance, so forget that. Anyway, the sound man came to me, because he didn't want to bug Prince, and said, "Matt, I got this problem with the sound in the piano. What do you think we can do?" I said, "There's this new MKS-20 thing. I think we should try that out, and put the Forte MIDI mod in the piano." So we put that in to trigger the MKS-20. I tried it out, and it sounded really good. Prince showed up for rehearsal a couple of days later. He had no idea that we had modified anything in the piano. He sat down at the piano and started playing, not saying anything. I walked over to him and said, "So what do you think of your piano sounds" He said, "Sounds really great! What did you do?" I told him what we had done because of the ambient noise problem. He said, "Wow! Good idea. Thanks a lot." The following year, the crew people came up and said, "We can't haul this big Yamaha grand around anymore. Besides, it's totally useless, since you don't even need the soundboard anymore." So I said, "Why don't you have a fake piano shell built, and mount a [Yamaha] KX88 in it?" That’s what they did, and they strengthened the top so that Prince could get up and do his stuff on top of it.
Rosie Gaines and Boni Boyer also used this piano set up, and Dr Fink had a MKS-20 and KX88 in his rig. The KX88/MKS-20 was replaced by a Roland A-90 for the piano shell on the Jam Of The Year tour.