I don't remember seeing that discussion here, but Mary Martin was very pleased with her singing on that album, calling it, ". . . one of the best I have recorded." The recording was made in 1957 (around August), right before Martin and Raitt opened in a limited run of AGYG for the San Francisco and Los Angles Civic Light Opera organizations. She says John Raitt's and her singing "wasn't pushed. We were full of enthusiasm. You can hear it on the record." She credits recording the album prior to the opening, rather than on their first day off after the opening (which was the custom then) as being the reason they sound "fresh". The televised version aired in November of the same year.
I don't recall how she sounded on the televised version, but I do remember thinking she sounded too relaxed on the album. I would have liked a more raw and belty sound.