Christopher Plummer, seen in September in Toronto, agreed to a reunion with the other Sound of Music actors on The Oprah Winfrey Show. (Darren Calabrese/Canadian Press)

It was The Sound of Music love-in on The Oprah Winfrey Show Thursday as Winfrey brought together the entire cast who played the family in the beloved musical.

Canadian actor Christopher Plummer, who played Capt. Von Trapp and Julie Andrews, who played Maria, were reunited for the first time in 45 years with all seven of the children who played their family.

Winfrey recapped incidents from the filming and people such as Rosie O'Donnell talked about what the film had meant in their lives.

Plummer took an irreverent approach to the reunion, recalling that he was reluctant to take the role of the authoritarian Capt. Von Trapp.

"I wanted to do a musical and that was what attracted me. The role left something to be desired," he said, recounting how disappointed he was at doing the film version instead of the original stage show.

Plummer, who blew his whistle in Capt. Von Trapp style to call the children — now all adults — to Oprah's show, thought there wasn't much scope for acting in such a stiff role.

"It wasn't human enough. There wasn't enough humour in it," he said, adding that he joked about calling it The Sound of Mucus.

"It could have gone overboard and become sentimental. And there were all these nuns around and it made you want to be irreverent," he said waggishly.

Andrews agreed that there was always the danger of the film becoming too sentimental.

She said she was 28 and just making her way on Broadway when she was cast in the role of Maria.

"I was in awe of this gentleman, a great dramatic actor and I was just a musical songstress," she said of Plummer.

"It made my career really, it was that big a movie," she said.

Andrews recalled shooting the opening scene in which she sings in an Austrian meadow.

"I remember it vividly. I walked across the fields at one end and the helicopter came from the other end," she said. "What I didn't realize was that every time the helicopter came round it would knock me down," she added, noting that it took multiple takes before director Robert Wise was happy with it.

Wise chose the seven children from among more than 700 actors, including a young Mia Farrow, who turned out for auditions.

The children — Charmian Carr as Liesl, Heather Menzies as Louisa, Nicholas Hammond as Friedrich, Angela Cartwright as Brigitta, Debbie Turner as Marta, Duane Chase as Kurt and Kym Karath as Gretl — all became stars.

They recalled their hijinks in the straight-laced Austrian hotel where they were staying, including switching shoes left outside the doors to be cleaned and changing everyone's breakfast order.

They spent nine months together during the shoot and became very close, they said.

"We are family. I feel it all the time. We get in touch at Christmas and holidays," Andrews said.

Plummer demurred, saying he had refused to agree to a reunion before this. But he told the story of being forced to watch the film 10 years later with a group of children and finding it was actually good.

"After about 10 minutes I was totally lost and I realized it was just about the best musical from a stage play that was ever filmed," he said.

Hammond told Winfrey they have plans for a book to commemorate the 45th anniversary of the musical, which is soon to be issued on Blu-ray.  

"We realized that we have this treasure trove of memorabilia home movies and stories," he said. "People for 45 years have asked us about the film and what it was like and we thought now is our chance to tell them."