Ritchie Blackmore utilizes the Roland GR-50 Guitar Synthesizer for his performances, with evidence indicating that the synth output is directly connected to a GR-50 rack unit, and he maintains a second unit as a backup. The GR-50 provides the distinctive octave effect heard during his shows. Observations from performances reveal that when Blackmore adjusts the synth volume knob, the octave effect audibly ceases, underscoring the GR-50's role in his sound setup. This information is corroborated by discussions on "Ritchie Blackmore Rainbow Reunion Gear 2016 - 2019" on The Gear Page.

"I have a Roland GR50 chopped up in a slim box behind my guitar."

Used in the 1990s, as known from the following:

adrianbelew.net, Discography, "inner revolution"

the guitar parts for This Is What I Believe In rely on a Roland GR-50 guitar synthe. with it I could pitch each string to have a different harmony note mixed with the original note of each string. thereby creating some very unique chords and running figures reminiscent of the style robert fripp and I played in the 80’s crimson.

Facebook, Adrian Belew, November 14, 2021 & adrianbelew.net, Discography, "here"

trivia points for Here:

[...]

•the ethereal sounds in Fly were made with a Roland GR-50 guitar synth. the song was written and recorded with a dobro (picture 4) tuned to DADDAD. I used a koto (picture 5) for the harp-like glissandos. the long low notes at the very end are my voice being manipulated.

Facebook, Adrian Belew, November 21, 2021 & adrianbelew.net, Discography, "the experimental guitar series volume 1: guitar as orchestra"

trivia points for Guitar As Orchestra:

•having released 4 pop-ish records in a row I was due to make a 180 degree turn. by this time I had worked extensively with 3 different guitar synth models (Roland gr-700, gr-50, and gr-1) and written a library of several hundred sounds. they weren’t samples, they were programs created by long late night experimentation. I felt it was time for someone to build an orchestra using only guitar.

•you can’t imagine the first-time thrill of playing my guitar and having it sound like a piano. a whole new universe appeared!

•having listened to this record for the first time in many years I was surprised at how ahead of its time it truly was. some of the better pieces would still make good film score material today. IMHO

•there really isn’t much in the way of trivia points since the whole record, be it tympani, harp, piano, or bassoon is guitar synthesizer. even the “audience applause” at the beginning was made with a guitar synth. so instead I will reprint here some of the liner notes from the record:

At 12:50 in this Rig Rundown for Lindsey Buckingham of Fleetwood Mac and Buckingham Nicks, his gear is displayed, showing a Roland GR-50 Guitar Synthesizer.

"I’ve been using BOSS pedals for about 15 years, maybe more … maybe closer to 20 years … and I dig ’em a lot. And I also used the guitar synthesizer, the very first blue one [Roland GR-300], then, in the ’80s, I used the GR-50. Now I have the most recent one [GR-20], and that thing is amazing."

In the [BOSS TONE CENTRAL] Jim O'Rourke Collection video by BOSSchannel on YouTube, Jim O'Rourke utilizes the Roland GR-50 Guitar Synthesizer to demonstrate the capabilities of the SY-300.

In this archived version of a December 2000 article from Sound On Sound, Underworld bandmate Hyde explains his then-current live rig. "Other elements are a TC Electronic Fireworx for guitar effects, Triaxis, Roland GR1 guitar synth, and Roland GK2A MIDI trigger -- I have a Roland GR50 chopped up in a slim box behind my guitar."

In one of his posts Pete Yates mentions his guitar synth Roland GR-50.

The Roland GR 50 can be seen in Sam Binga's rack during his interview with Future Music Magazine.