As far as I know, night, Mother is not a musical or a musical performance. It is a drama which uses dialogue as its most prominent style of discourse. It is also noted and highly praised (Pulitzer Prize for Drama in 1983) for its Realism. The play runs about 1 1/2 hours. And this is displayed by a real clock on stage, so the events of the play take the course of a real 1 1/2 hours within the play itself. It so strictly adheres to Realism that I think making or converting it into a musical would take away from that Realistic experience. However, it may have been done, and it's completely possible that a musical interpretation would work, but I think it would shift from a Realism style to something more postmodern. The play is also noted for its stoicism (its lack of sentimentality) and adding an emotive aspect like music would reinterpret the play - which could work - I'm always up for reinterpretations, but it would change the play I'm sure.