Albums recorded in something akin to Cinemascope? Never thought of it, though back then it likely would seem a "sound" enough idea. (I'm probably wrong. Cinemascope and Cinerama was even then magnetic recording, can't remember for sure).
BUMP!
I see that I was wrong with regards to it being optical soundtrack (it is magnetic) but according to this description, it gave superior sound:
http://www.musicboxtheatre.com/70mm.html
70mm SOUND
Left - Left Extra - Center - Right Extra - Right - Surround.
Six discrete, magnetic tape, channels of sound. Two are on the outer edges of the film and one between the sprocket holes and the picture on both side of the film stock (the black vertical lines shown above). Until recent advances in Digital sound reproduction, 70mm magnetic tape stereo was the apex of state-of-the-art audio reproduction.
The Music Box utilizes new state-of-the-art JBL theater speakers behind the screen for Left, Left Extra, Center, Right Extra and Right sound channels. 6 Altec Lansing / Seaburg presentation speakers are installed for surround, plus four 16" Yamaha Sub Woofers for Dolby, Dolby SR and DTS sub-bass channels; powered by 1000 watt Crown power amplifiers.
Not all 70mm film presentations were photographed using 70mm cameras. It was not unusual for studios to photograph movies in less expensive 35mm format and process them in 70mm just to utilized the marvelous sound reproduction of 70mm. Although the quality of picture clarity suffered slighty in the transfer from the smaller frame to the larger (enlarge a picture on your computer screen by 3x) the difference in sound presentation more than made up for the minor disparity of image. New digital sound process allows full frame 70mm film to be remastered in DTS digital sound. The Music Box Theatre has been priviledged to present new 70mm prints of Dr. Zhivago, Patton and now Lawrence of Arabia in 70mm and DTS digital sound reprocessed from the original magnetic sound track.
Not all films photographed in 70mm were seen in 70mm. Outside major market areas most films shot in 70mm were presented in 35mm Cinemascope format. Very few theaters outside of city centers had 70mm projectors. Today's re-release of 70mm restorations are even rarer "special event presentations" since even fewer major market area cinemas have 70mm projection capabilities.
70mm film projection begins with a large, full frame cell to achieve the projected image. In surface area, this 70mm cell is about 3 times bigger than a standard 35mm cell. The larger film cell allows for a brighter picture (movies are light projected through film and reflected off the movie screen) and sharper focus, corner to corner, with no distortion of image as found in anamorphic presentations (i.e.: Cinemascope).