Hello,
Here are your answers:
The existing "Composite Mix" currently at Imagineering Sound Department elements are as following:
They have the isolated pre-show music/fx cues in FULL stereo. Real stereo that bounces around like you wouldn't believe. They also have a complete composite of the pre-show also in true stero. The track that you are refering to "Mysteries of the Atom" was NEVER used in ATIS. I researched this for years and I was finally able to confirm this (through listening to many live recordings). I found out why a lot of people believe Mysteries to be connected to ATIS: First of all, this track was recorded (but not used) for the 64 world's fair for Progressland. It was later used in a 65 promo for the upcoming New Tomorrowland and used it when the narration starts on Inner Space all the way thru Space Mountain (which never came in 67). Because of this use, many people associated it with ATIS and when the Disneyland Forever system came to be, the people involved actually mixed this track in with the pre-show (since they were both 5 minutes long). People who have heard this new mix (never actually released on Forever) of course now associate Mysteries with ATIS. This was a mistake. Now moving on... They also have a composite ride-thru mix of the actual ride...in MONO. They actually tinkered with it to make it a slightly fake stereo, but it is mono. Same story with the exit song "Miracles from Molecules": MONO. Another interesting tidbit is that Miracles has a sound effect that ends the song and loops again. When that track was released on Forever, that short sfx was cut off. Other interesting ATIS tracks exists somewhere. There is a full Paul Frees early version of the narration as well as a couple demos of the Sherman Bros. song. There is also an alternate version of the exit music which mixes a different version of the song with comm chat and sfx. On top of all these tracks, there is also the 7" record release which has a differently edited version of Miracles (with some sfx and with no instrumental portion of the song) with the great B side "lounge" instrumental of Miracles. Of course they also have an isolated Paul Frees narration and the load and unload spiels. That's about it. The masters still exists, but not at Imagineering Sound Department. To achieve a new Ride-thru for the box set, Randy will have to dig (and pay $$$$$$$) to get the masters transfered from the vaults and hopefully they were recorded in Stereo so he can do a new and improved stereo ride-thru. Here's hoping....
So back to your basic question: Mysteries (which is in stereo) was NOT used in ATIS. And hopefully Disney will want to pay big bucks to get the original masters transfered from the vaults for our listening pleasure. Any more ATIS questions, let me know. I've researched this attraction soundtrack for years...
Your friend,
Louis