Anne Frank: The Diary of a Young Girl, considered the most widely read book on the Holocaust, is being turned into a Spanish musical.

Anne Frank, 13, her family and four others hid in a secret area in the Amsterdam office of her father, Otto Frank, during the German occupation of the Netherlands in the Second World War.

Anne Frank, pictured here in April 1941, hid with her family in an Amsterdam office for 25 months during the Nazi occupation of the Netherlands. Her diary, which was made into a book, will be the basis of a new musical.
(Anne Frank Foundation/Associated Press)

The family was betrayed and subsequently sent to concentration camps. Anne, her sister and mother died in the camps.

Only her father survived and in 1947 first published Anne's diary, which details the minutiae of life during those months in the secret apartment. Since then, it has undergone several revisions, been translated into dozens of languages and adapted into films, television movies and plays.

The Anne Frank Museum in Amsterdam is endorsing the musical concept and on Friday, officials guided the 22-member cast and directors through the space where the family hid.

The museum includes the house where the family hid for 25 months, from 1942 to 1944. It gets about a million visitors a year.

"I think it's very special and a very important detail to come to this house," said Isabella Castillo, 13, who will play Anne when the show opens Feb. 28 at Madrid's Calderon Theatre.

Castillo says she was struck by how tiny the space was and says how honoured she feels to be playing Anne. She also says she has a few things in common with Anne.

The Frank family emigrated from Germany to the Netherlands in 1933, when Anne was four. Castillo's mother defected from Cuba while Isabella was a toddler and they lived in hiding in Belize before immigrating to Miami.

"It's nothing like [what the Frank family went through], but a little bit."

Diary compared to an opera

Rafael Alvero, who developed the concept, admits that the idea of a musical seemed ridiculous to him at first. But, he points out the diary of Anne Frank can be compared to a tragic opera.

"Of course this [staging] is emotional," said Alvero, who worked on the musical for 10 years. "The thing we want to do is … through the music, to understand the story better."

Members of the cast said they felt emotional at being in the space that they had imagined many times.

"When I was coming in, I started to feel touched by everything I saw, and I thought that wouldn't happen," said Rocio Leon, playing the part of Anne's sister Margot.

The cast performed several numbers from the show and received an enthusiastic reception by museum staff.

With files from the Associated Press