Anna Moffo's voice was a gift from God. One of those typically beautiful creamy lyric voices (in the same mould as Renee Fleming, Kiri Te Kanawa and Teresa Stich-Randall), she was born to sing Mozart, bel canto, the Villa-Lobos Bachianos Brasileiras No. 8, and more.
Even here, as a young performer at the beginning of her career, the voice is magic. She herself, although she has yet to bloom into the full physical beauty that will be hers, is extremely pretty in this filmed version of Sonnambula. But of the accomplished actress that is also to bloom... as yet there is little, if any, trace. She has a lovely smile, and a good "I am agonised" expression, but one really needs more than that. We know that she DID develop and become a good actress, and that her voice continued in its beauty...
However, do not think to find any well-developed acting technique in this film version of the opera. It often has a quaint charm about it, but the acting is often atrocious - by EVERYONE. The chorus are particularly culpable for very bad "stage" moves which are under-rehearsed and cringe-worthy. No one is fully convincing... although some are less convincing than others.
As far as the singing goes... well, it is mostly adequate. No one else matches Moffo's exquisite sound, but the Elvino is okay, the Count is better, and the Lisa sounds far too much like a tin whistle to please.
As a historical document of the young Moffo, this is well worth the price. But as a well-staged or well-sung performance of La Sonnambula - no. Get this for Moffo's voice and youthful loveliness - in that sense, you will not be disappointed.