The 35-year-old singer, who released her debut album in February, was on stage for the Festival Léo Ferré in the Church of the Cordeliers in the village of Goudron in the Lot region in south-west France.
Her cause of death is unclear but one report claims she may have been electrocuted, although it is unclear what may have cause this, with other reports citing she suffered a cardiac arrest but was unable to be saved.
She had a camera on stage and sung barefoot and it is speculated that she may have touched an electric device that was live on stage, reports La Depeche.
They also report that her death ‘provoked a very lively emotion among the spectators’.
Police have opened an investigation to ‘search for the causes of the death’ and it is believed they will be analysing the images from various videos taken on the night to assist with their inquiry.
They ‘will see in the next weeks if a requalification is necessary’, the prosecutor’s office said, according to Europe 1.
The festival has now been cancelled.
The organisers of Pic d’Or said in a statement: ‘It was with great emotion that we learned this morning of the death of Barbara Weldens, our Pic d’Or 2016 at a concert last night in Gourdon in the Lot, obviously electrocuted.
‘Our team is deeply disturbed by the brutal disappearance of the artist who had appeared on the stage of the Theater des Nouveaux on May 20th, during our last edition.
‘A radiant woman, full of energy and talented, and of course we think of all her family and her loved ones.’
Weldens was an up-and-coming singer and won a young talent award in the Jacques Brel Young Talent Competition last year.
Her debut album is titled Le grand H de l’homme.