what was the name of the film made in late 60's thru 70's about a family that lived in a dome under sea

Question

This was a singing family and I beleive seen on TV but maybe in a theatre. Late sixties to early seventys

Answer 1

"Hello Down There"
http://www.imdb.com/title/tt0064417/

Answer 2

...maybe "Captain Nemo and the Underwater City", from 1969???

The story DOES involve a domed underwater city, and a family forcefully taken to live there, but I don't remember any specific story preponderance of 'singing', per say; I'd be most interested in finding out what you're ACTUALLY looking for...