According to Reverb, Mike Shinoda used the Yamaha KX5, which is highlighted as part of Linkin Park's gear history.

"The remote keyboard was actually a transformation of the Yamaha KX5, but customised for my own needs - the visual, and the ability to send program change data to the Fairlight and the Emulator. The other one - the big round one - was actually a prototype of what I'm developing now. It's a kind of audio visual instrument that can interface between the musician, synthesisers and lighting effects. In other words, when you are pressing keys you are not actually playing music like on a chromatic keyboard, but you can actually switch on musical effects and synchronise them with the lighting. At each key you have a MIDI signal, along with other digital and analogue signals, to control other things."

A.R. Rahman utilized the Yamaha KX5 during his 1990s music concerts and film compositions, as showcased in images on Videosinspire.

On his performance in Media Bahn Live in 1986.

In this photo circa 1987 you can see him playing a KX5 while Michael Brecker is playing a saxophone

Gabriel can be seen on the back cover of this bootleg album playing a Yamaha KX5.

0:00 The KX5 is a midi Controller Keytar

"There are three sound sources", he explains. "There's an Akai S900 which has samples transferred from the Fairlight Series III, a Roland Super Jupiter and a Roland MKS20 piano module. All of those go into an Akai MIDI mixer and through two effects: a Yamaha SPX90 and an Alesis Midifex. They're all mapped by a Cooper Electronics MIDI Link, and I play them from a KX5 slung round my neck and a couple of Yamaha pedals. They put out program numbers to the MIDI link and that sends out separate program numbers to everything else. In other words I'll build up an entire patch with sound sources, a mix, effects and a stereo output, and store it. Then, when I send one program number into it from either the keyboard or from the pedal, it'll send the appropriate numbers out."

Lights has used this specific keytar multiple times while performing live.

On the right side of Howard Jones, you can see that customised keytar

http://www.matrixsynth.com/2005/11/howard-jones-20th-anniversary-concert.html

Jan Hammer rocks out with his Fairlight and Yamaha KX5 remote keyboard on BBC Rock School series 2 from 1987

Playing Yamaha KX5 in this video.