On my first trip to NYC in 1977 I discovered Colony.
I loved the way they had the Lps organized: Original casts: In print seperated by label and then (more or less) alphabetical. Then all the out-of-print ("Cut-outs") Lps, again by label. They had nearly EVERYTHING: really rare items like SAY DARLING, ALLEGRO, the Ann Southern TV cast of LADY IN THE DARK, and so many others. All priced anywhere from $50 to $250. At the time the regular list price of Lps was $6.98 and discount stores in Manhattan often sold them for $3.99!
But Colony was fun to browse, and even in later years when the Lps were moved to library shelving in the back of the store it was a good way to pass time between a matinee and an evening show. Now the vinyl is gone and the Cd's are in locked cabinets. It's just not the same.
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