Yes, the "music box" image also occurred to me, and it reminded me of the opening title sequence of the 1975 film AT LONG LAST LOVE (featuring Cole Porter's songs) which shows a music box with a pair of couples waltzing away.
Appropriately - to the tune of "Just One of Those things" - the waltzing stops, the couples separate and change partners resuming the waltz.
It's an apt summation of the plot to come(convoluted and poorly told in the film) but also stolen from Hal Prince's and Pat Birch's original staging of the opening of NIGHT MUSIC where the waltzing and re-coupling couples foreshadowed the plot.
Cast albums are NOT "soundtracks."
Live theatre does not use a "soundtrack." If it did, it wouldn't be live theatre!
I host a weekly one-hour radio program featuring cast album selections as well as songs by cabaret, jazz and theatre artists. The program, FRONT ROW CENTRE is heard Sundays 9 to 10 am and also Saturdays from 8 to 9 am (eastern times) on www.proudfm.com