Clare Cunningham says she got a voicemail from one of Thundermother's founding members around eighteen months ago after she posted some of her own material on Youtube.
She was told that the band was looking for a new lead singer.
“At first I was very sceptical and had no idea of what was involved – and I was very busy with my own band I had in Cardiff at the time,” she told the Irish Independent.
She was initially so busy that she didn't respond to the message.
But according to the newspaper she was persuaded by original band members Filippa Nassil and Giorgia Cateri who had also recruited bassist Linda Ström and drummer Tilda Stenqvist.
They told her that her first show would involve opening up the Metaltown festival for Motorhead, a big name on the rock music circuit.
“That obviously caught my attention and so we discussed it further and within a couple of days I was learning ten brand new songs.”
Cunningham described her first gig as "insane" and said that "from that very moment walking onto that stage my music career was about to change".
The band are currently touring Europe, with dates in the UK and Ireland this week and back in Sweden at the end of the month.