Village of the Giants (1965)
Tisha's film premier definitely wasn't The Sound of Music . . . but it did feature the Beau Brummels in their only group appearance in a feature film.
It also included Lloyd Bridges' son Beau and Mickey Rooney's son Tim, as well as Tommy Kirk, Johnny Crawford, Joy Harmon, Bob Random . . . and eleven-year-old Ron Howard as "Genius" who discovers a growth serum that produces six-foot-tall ducks with three-foot-long drumsticks that promise the end to world hunger until . . .
. . . the growth serum is misappropriated by Beau and Tisha's band of teenage delinquents, who use it to grow to gargantuan size and take over the town!
Village of the Giants, in which Tisha (in her own words) just "grinned and bared it," may have been a drive-in T&A bra-buster but it's one that, looked back at over thirty-five years later, is actually a rather charming piece of Sixties camp reappearing from time to time on cable channels.
And as for those six-foot-tall ducks, well. . . . It wasn't Tisha's first encounter with fowl friends.