Album3: Rare & Unreleased Recordings From The Golden Reign Of The Queen Of Soul, Atlantic/Rhino B00122MKI0, 16 October 2007.
The churchy duet from the We Love You Madly tribute to Duke Ellington (1973) was also released on Aretha's Unreleased Recordings album, in an edited, remastered version.
The album version is 6:01, where the video version - including Ray's rather extensive spoken intro - is only 4:46. During the first minutes the album producers also added Hammond organ and keyboard sounds (and I think some percussion) to the track, numbing Ray's original piano playing to almost unhearable levels for the main part of the tune.
The result, however, is pleasing; the only odd thing is that the album producers didn't make explicit that they a) went back to the original, longer, taping, and b) didn't specify what they changed and added.
The details listed by Michel Ruppli's Atlantic Discography (sub Master #26222) are: "vo RC, AF, JC" (i.e. that Ray Charles, Aretha Franklin, and James Cleveland's gospel singers took care of the vocals).
David Ritz' liner notes to the album explain nothing, and erroneously state that Aretha played piano and Ray played electric piano, quite different from what can be seen in the video. The other musicians credited by Ritz are Dave Grusin (keyboards), Kenny Burrell (guitar), Chuck Rainey (bass) and Paul Humphrey (drums). They no doubt contributed to the original show, but I very much doubt if Gruisin played keyboards in the original, videotaped version of Ain't But The One.*
I suspect that in an interview (cf. 1, 2) Jerry Wexler, who (executive) produced the album, may have been about to tell something about 'post producing' this particular track when the interviewer diverted him into replicating a well known, similar, anecdote about the 1971 release of Aretha & Ray's famous duet on Spirit In The Dark. My conjecture, therefore, is that it was Wexler who may be 'blamed' for also 'improving' this release of Ain't But The One.
From Unreleased Recordings: