Carrie Underwood's live performance as Maria Von Trapp in the "Sound of Music" special which aired on NBC last Thursday failed to impress the original cast of the classic film.

Apparently, Kym Karath, who was the original Gretl Von Trapp in the 1965 film, liked everyone but Carrie based on the tweets she posted after the show. Julie  Andrews, meanwhile, played the original Maria who fell for retired naval captain George Von Trapp.

Kym was invited along with Charmian Carr and Angela Cartwright, who played Liesl and Angela respectively, to watch Carrie in action.

She tweeted afterwards: "Mystified & disappointed so far by SOM special. So far only happy with Stephen Moyer."

Although more famous for playing the lead vampire in the HBO series "True Blood," not many people know that Stephen is actually a certified theatre performer. In the Sound of Music live performance, he plays Georg Van Trapp.

"Must admit some scenes are actually painful to watch...Love Carrie Underwood but this role is just not right for her. She is lovely her voice is beautiful but acting is wrong," Kym added.

However, the former American Idol winner could not be fully faulted for getting mixed reviews mainly from social media sites. Apart from the 2011 "Soul Surfer" as well as a guest appearance in a TV sitcom, Carrie Underwoods has never had to show her acting chops before.

Carrie also refused to let the bad reviews get to her.

"Glory to God tonight...I couldn't be more proud. What a tough thing to pull off and we did it! I am so blessed!!!" Carrie  Underwood tweeted afterwards.

And while she might have failed to impress Gretl Von Trapp, she at least won the ratings game. According to the preliminary report by Nielsen's, the Sound of Music recorded 18.5 million viewers who watched her belt out the classic songs.