I had seen two very fine productions of the play before the musical version was announced. I am not convinced that the music adds anything significant to the drama, but the musical is a valiant (and mostly successful) adaptation.
The play, however, was riveting. Much is made of the sex scene in the musical. In the play there were several including one solo and one group masturbation scene. (In the latter the boys were on stage wearing white briefs with tiny flashlights inside. They moved the lights to simulate the act and as each one finished they turned off the light. It was brilliant but the audience was dead silent in that sequence...almost like no one was breathing!)
My most vivid memory was of the final scene where the actor playing Moritz was flown in on a "cloud" appearing headless with his head under his arm. (The actor playing Moritz put his own head through the arm of either a dummy or a second actor costumed to look headless.) It was a startling image to say the least.
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