LONDON (AP) ― Margaret Thatcher chose Beethoven, Michael Caine picked Frank Sinatra and boxer George Foreman selected The Beatles’ “All You Need is Love.’’

They are among almost 3,000 guests who have appeared on the radio program “Desert Island Discs,’’ a British broadcasting institution that turned 70 on Sunday.

The show’s simple format hasn’t changed since 1942: Ask an illustrious or famous figure to choose the eight pieces of music they would take with them to a deserted isle, and talk about what the tracks mean to them. At the end of each program, the guest is sent into imaginary exile, along with their choice of a book, a luxury and one of their eight records.

Almost 3 million listeners tune in each week to the show, which has stranded royalty, prime ministers and movie stars, as well as scientists, poets and philosophers.

Its success is a mark of radio’s enduring popularity in the age of the Internet and high definition TV. Host Kirsty Young said its strength lies in the “unique blend of a castaway’s life and the music that forms its soundtrack.’’

“At best it displays the frailties and strengths of the human condition ― how our creativity, grit and humanity can see us through,’’ she said in a BBC radio documentary marking the anniversary.

Young told the Radio Times magazine that scientists made the best guests, because they often had not been interviewed before.

“Politicians are awful, especially when they have the responsibility of office, because they have to be careful,’’ said Young, one of only four hosts the show has had in 70 years.