Dick Van Dyke Recalls Crying First Time He Heard “Mary Poppins” Music: 'The Most Beautiful Thing' (Exclusive)

"I couldn't believe, one tune after another," he said. "I wept"

Dick Van Dyke had an emotional reaction upon hearing the music of Mary Poppins for the first time.

The actor, now 98, sat down for an interview as part of ABC News' special The Untold Story of Mary Poppins: A Special Edition of 20/20, timed to the 60th anniversary of the iconic Disney movie.

In a clip shared exclusively with PEOPLE, Van Dyke remembers crying when the Sherman Brothers first played the now-iconic songs for him.

"I couldn't believe, one tune after another," he says. "I wept. It was just the most beautiful thing I'd ever heard."

Related: Dick Van Dyke on Filming Mary Poppins with Julie Andrews: ‘She Was Cool as a Cucumber’

Van Dyke famously starred as a chimney sweep named Bert in the 1964 film opposite Julie Andrews as the titular magical nanny. Mary Poppins won five Oscars, including Best Actress for Andrews, now 89, plus Best Original Score and Best Original Song ("Chim Chim Cher-ee") for the Sherman Brothers, Richard and Robert.

Some of the memorable songs from the movie musical include "A Spoonful of Sugar," "Jolly Holiday," "Step in Time" and "Let's Go Fly a Kite."

The PEOPLE Puzzler crossword is here! How quickly can you solve it? Play now!

During the interview, Van Dyke recalled working with Walt Disney, who died in 1966. "When I met Walt we hit it right off. We both admitted that we just pretended to be grown up and that we were still kids," he said.

"I went into his office, and he had water-color paintings of all the scenes in the movie. By the time we got through with that, I was just so excited."

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories.

The two-hour Untold Story of Mary Poppins special features rare footage, photos and stories from the living legends, and it is part of a two-night event.

The Untold Story of Mary Poppins: A Special Edition of 20/20 airs Wednesday, Nov. 27, at 9 p.m. ET then streams next day on Hulu and Disney+. Then on Thursday, Nov. 28, The Wonderful World of Disney presents an airing of Mary Poppins.