Music in the trailer

We've discussed the absence of music in "Executive Suite" on another thread, but there is some very beautiful music in the theatrical trailer. Unfortunately I've only caught part of it, twice, when TCM was running the trailer between other movies over the past couple of months, so I didn't hear all of it. (The trailer will be on the forthcoming DVD.) It was a common practice in the Hollywood of that era for studios to take music from previous films and lay them on the soundtracks of trailers for new films whose own scores hadn't been completed yet. Though I didn't see the entire trailer, I didn't recognize the music in the portion I did see and hear, and I'm wondering whether that music might have come from a score commissioned for E.S. but never used when the decision was made to release the film without a score.

Anyone recognize the music, or have any ideas about it?