In 1969 Steve Winwood used an RMI Rock-Si-Chord in Blind Faith through out the concert at Hyde Park. It can be seen on the youtube video labled "Blind Faith in Hyde Park, 1969." It can be clearly seen as a close up when he starts the song "Had To Cry Today" (39:47)

In this photo, Brian Wilson can be seen playing a RMI Rock-Si-Chord with the Beach Boys, as Wilson joined the band for a surprise appearance at the Whiskey a Go Go in 1970. Several other photos from this show have surfaced, which can be found here, here, and here.

According to this article from Pitchfork, Terry Riley used an RMI Rock-Si-Chord on "A Rainbow in Curved Air."

Side A’s heavily overdubbed title track features the composer on a range of keys: electric organ, electric harpsichord, rocksichord (also a favorite of Sun Ra’s), as well as two percussion items (dumbec and tambourine).

Sun Ra played a RMI Rock-Si-Chord on his 1970 album The Night of the Purple Moon. The back cover of the record states that Ra plays a "ROKSICHORD" on every song on the record. He also played one live at various times throughout the 1970s.

In this photo, Kerry can be seen behind an RMI Rock-Si-Chord at Advision Studios. This photo was posted by Gentle Giant on Instagram in 2020.

"Additional colour on Music from Big Pink came from an RMI Rock-Si-Chord, which supplied the shimmering percussive sounds on "In a Station" and other tracks."

This photo was posted by Quasi's official Facebook page in 2020 with the following caption:

Happy birthday to this guy, the world's greatest Sam Coomes seen here back where Quasi began, the X-ray Cafe and the RMI Rock-si-chord. Keep on kicking ass Sam! We all love you!

The hinges and case on this instrument differ from other Rock-Si-Chords, and the legs do not match the typical RMI-style legs used on practically every other keyboard they produced. If this is in fact an RMI Rock-Si-Chord, it is likely that it has undergone some significant modifications over the years.

Additional photo here.

Jorgensen posted this photo on Instagram in 2013 with the caption, "Adios old buddy. You're going to a new home and someone who will care for you better than I ever could. #Rocksichord #RMI"

*"For the technically-minded, Wells informed B.I that Jimmy Greenspoon plays a Hammond B.3 and a Wurlitzer electric piano. Also a Roxicord which is a cross between an organ and a piano" * -Beat Instrumental Dec. 1972 [How We Make Hits-By 3 Dog Night]

Greenspoon can be seen at his rig sitting in front of him and to his left a black Wurlitzer (145b??) on top and Rock-Si-Chord beneath.

In this photo, Nickey Barclay can be seen playing an RMI Rock-Si-Chord while rehearsing with Fanny. The badge on the back of the instrument appears to read “RMI Rock-Si-Chord.” This instrument is all black, which was common of late Rock-Si-Chord models.

An RMI sound can be heard on the band’s hit song “Ain’t that Peculiar.” I haven’t found real evidence that Barclay played a Rock-Si-Chord or Electra-piano on the track, but a Rock-Si-Chord seems likely given this photo.

(Note: I previously entered this instrument as an RMI Electra-piano before noticing the badge.)

This photo shows Jerry Yester playing an early RMI keyboard at a Lovin’ Spoonful concert. The model is either a Rock-Si-Chord or an Explorer, as both featured this three-tiered case design at various points in production. I believe it to be a Rock-Si-Chord, as one RMI ad from an October 1967 edition of Billboard reads, “Take a live group like THE LOVIN' SPOONFUL, they're turned-on with ROCK-SI-CHORD and have become a living legend.”

The photo was originally posted by Fordham University in an article about past on-campus concerts, including the Beach Boys & Lovin’ Spoonful concert at Fordham’s Rose Hill Gymnasium on March 18, 1966. This date raises some questions, as Yester didn’t join the group until May 1967. I believe it’s most likely that Fordham simply included an image that wasn’t from the actual 1966 concert at Fordham.

These photos depict a prototype RMI Rock-Si-Chord that belonged to Michael Kac of the 1960s rock group Mandrake Memorial. He can be seen playing it in the only surviving live footage of the band, which is available on YouTube here. The keyboard was up for sale on eBay in 2023. The seller says they bought it from a local musician's estate. The shape of the keyboard is uncharacteristic of later Rock-Si-Chord models.

Record Collector Magazine had this to say about the band's first album and use of the Rock-Si-Chord:

The quartet quickly gained a following in Philadelphia, and were able to develop a distinctive sound when a representative of Rocky Mountain Instruments asked if they’d be interested in using a prototype of a new electric harpsichord they were hoping to market, the RMI Rock-Si-Chord. As Kac has since put it: “We realized immediately that it gave us something nobody else had.” Despite that break, they had their share of adversity over the course of 1967, before the tide began to turn their way following a support slot with The Strawberry Alarm Clock. Though they’d recently had a No. 1 hit with Incense & Peppermints, The Mandrake Memorial blew them off-stage, greatly boosting their reputation in the process.

Having signed to the small Poppy label, their likable debut appeared the following spring (featuring prominent Rock-Si-Chord, as Rocky Mountain Instruments were doubtless pleased to note). Reviewing them as support act for The Turtles at Steve Paul’s Scene club in New York on 18th September 1968, Billboard called them “a very different group with an unusual presentation”, adding that “their performance has one number drift into another, sometimes with fine transitional music by Michael Kac on keyboard.”

Craig Anderton, singer of the Mandrake Memorial, said the following about the Rock-Si-Chord in an online forum:

My band Mandrake had the first prototype Rock-Si-Chord, and it was an essential part of our sound. This is probably the best example of it being used on a song. It's from 55 years ago, and yes, that's me on guitar :) The song after "Next Number" starts out with the electric piano sound that the Rock-Si-Chord also had. I believe these were the earliest recordings of both sounds, and probably, the only ones because this was before they went into full production. The later Rock-Si-Chords didn't sound as good to my ears as those early prototypes.

RMI also made kickass keyboard amps. I started using them on guitar, I liked the flat-response/full-range behavior. I stopped using conventional guitar amps in 1968 and went through FRFR keyboard amps, and getting my sound before it hit the amps. Also I doubled between guitar and keys, and it was easier to get the guitar to sound right through keyboard amps than it was to get synthesizers sounding right through guitar amps.