On a 1958 Columbia Lp of Broadway Overtures, conductor Lehman Engle explains a bit about how an Overture gets constructed.
Although it is the first item heard it is always the very last item to be assembled. The orchestrator meets with composer, producer, director and they try to select the songs that would most likely have a life outside the show, the songs that work best orchestral, and also avoiding a song heard too early in the program after the Overture. Once the 3-6 songs are selected the orchestrator must arrange into a medley, creating connecting lines and transitions. It is very last minute an often the copyists must work overtime to get the parts ready for the first performance. When he wrote these notes in 1958 most shows still went out-of-town for try-outs and he commented that sometimes a song featured in the Overture was cut and it had to be removed from the Overture. Or, sometimes an un-expected song became a hit and sometime the Overture was reworked to include it. And often time and money would run out so the Overture had to stand as it was. (For the post-Broadway, Richard Rodgers had the Overture altered to include "I enjoy being a girl.")
There was a time when EVERY Broadway show opened with a full 4-5 minute Overture. Today, it's just a short prelude that segues right into the opening number. I think shows do move faster now, but what we have lost!
Can anyone name a current Broadway show that has a full, stand alone Overture?
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