Lynn in an undated file photo.

Vera Lynn praises the soldiers who kept her safe while she sang in Burma during World War II, in a programme celebrating her 100th birthday.

The Forces’ Sweetheart told the BBC documentary about the stories behind her rise to global fame, including her posting with the Entertainments National Service Association in 1944.

Remembering the moment she woke up to find four Japanese fighters prowling outside her hut, she said: “I always knew I was being very well looked after, the boys never left my side.”

Dame Vera, who turns 100 today, also recounts the night British soldiers rushed to hold her piano together when it fell apart mid-performance following a bumpy drive through the jungle.

But in the programme she admits that, when she signed up for the position to help boost troops’ morale, the heat was one aspect she did not fully think through.

“Trying to put make-up on was my first mistake,” she says, “and I shouldn’t have got a perm.”

I always looked at the lyrics first because I thought they were more important and, if I liked them, then I would look at the tune

Presented by Katie Derham, the programme takes viewers through Lynn’s journey from singing in working men’s clubs in London from the age of seven, to hosting her own radio show Sincerely Yours, where she passed messages between soldiers fighting overseas with their families at home.

Holding her medal of the Member of the Order of the Companions of Honour at her home in Ditchling, East Sussex. Photo: Lucy Carnaghan Photography/PA Wire

She continued to sing and appear on television after her return from Burma, eventually becoming the first British artist to make number one in America.

Her 2009 compilation We’ll Meet Again, which shares its name with one of her biggest global hits, made her the oldest living artist to top the UK album charts.

Stars such as Miriam Margolyes, Barry Humphries and Sir Paul McCartney also speak about the renowned singer’s influence, along with war veterans who met her in the field.

One veteran explains how he took a dangerous two-hour trip through the Burmese jungle to meet her, while another described hearing her sing as “the best bottle of medicine”.

Having never had professional musical training, viewers will learn how the early days of her career saw Lynn spend “hours leafing through sheet music” in London’s Denmark Street to find the songs she wanted to perform.

“I always looked at the lyrics first because I thought they were more important and, if I liked them, then I would look at the tune,” she says.

Lynn’s daughter, Virginia Lewis-Jones, shows Derham a selection of her mother’s fan mail, which she still receives on a daily basis, including a birthday message from the late Queen Mother.

New album marks birthday

To celebrate her 100th birthday, Vera Lynn has released a new album.The record features new re-orchestrated versions of her most beloved music alongside her original vocals.

It is thought the collection will make Lynn the first singer to have released a new album as a centenarian.

The album also features a previously unreleased version of Sailing – a surprise find as it was not widely known she had recorded the track.

Lynn is joined by a line-up of chart-topping British singers on the album, including Alfie Boe on We’ll Meet Again, Alexander Armstrong on White Cliffs of Dover and Aled Jones on As Time Goes By.

Auf Wiederseh’n Sweetheart, which saw the veteran musician become the first British singer to reach the top of the US Official Charts in 1952, also appears on the record.

It’s truly humbling that people still enjoy these songs from so many years ago

Dame Vera said: “It’s truly humbling that people still enjoy these songs from so many years ago, reliving the emotions of that time ­ I was after all just doing my job as a singer ­ and it’s so wonderful for me to hear my songs again so beautifully presented in a completely new way.”

She also celebrated her birthday yesterday with a charity concert showcasing some of the best of British talent at the London Palladium. The one-off spectacular raised funds for her children’s charity and features Armstrong and singers Blake and Hayley Westenra.

She has previously described the prospect of reaching 100 as “an incredible adventure of song, dance, and friendship”.