ASSASSINS played at Playwrights Horizons in January 1991 ... so IF it had transferred to Broadway it would NOT have been up against CITY OF ANGELS, GRAND HOTEL, MEET ME IN ST LOUIS and ASPECTS OF LOVE which were in the 1989/90 season.
If it opened on Broadway in the spring of 1991 it would have competed against MISS SAIGON, THE WILL ROGERS FOLLIES, THE SECRET GARDEN and ONCE ON THIS ISLAND. (Season 1990/91.)
SO the question really is: Do you thing ASSASSINS would have beat WILL ROGERS FOLLIES to win Best Musical in 1991?
(And what lamebrain posted the question with ASSASSINS in the wrong season? Look at the opening dates in the CD booklets!!)
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