The pre/post show music in BOEING BOEING is, as you know, American hits from the 60's that were recorded in Italian, German, and French (vis-a-vis the 3 fiancees, of course).
They were complied from several original sources, but I know this was one of them:
http://www.amazon.com/Swinging-Mademoiselles-Groovy-French-Sounds/dp/B0009VBTSW Incidentally, Christine Baranski (goddess - make sign of the cross) told me that the fun music was the primary reason the sound designer for the show, Simon Baker, was nominated for the first-ever "Sound in a Play" Tony, because god knows he didn't do any mics on the stage or actors. (Those poor folks scream their way through that show 8x's a week!)
One more note: Don't confuse these songs with the "original music" that plays at that oh-so-fun curtain call and at the end of Act I. That's by Claire Van Kampen, who, like Mark Rylance, came from the UK -- specifically, she did a lot of work with mark at the Globe.
To get a copy of that, you'd probably have to email her directly. I don't think they're planning on marketing it.
Peace.