Among the new pledgers are Brighton Music Conference, Cambridge Folk Festival and New Music Biennial, who join the likes of BBC Music, The Great Escape and Liverpool Sound City in backing the scheme which aims to achieve or maintain a 50:50 gender balance by 2022.
The scheme was announced earlier this year by PRS Foundation, the UK’s leading funder of new music, as a means to celebrate and invest in the talent of female music creators and innovators.
The charity will officially announce the 40 further festivals joining the pioneering pledge today (4 May) at Liverpool Sound City.
It will also present a Keychange Inspiration Award to music and arts pioneer Jayne Casey, best known for her involvement in the Liverpool punk and new wave scene in the 1970s and 1980s with Big in Japan, Pink Military and Pink Industry.
Speaking ahead of the event, the charity's chief executive Vanessa Reed said: 'We’re thrilled that Liverpool Sound City has joined the Keychange partnership and is hosting an event which celebrates the fact that another 40 festivals have joined since we launched at Canada House a few months ago.
'It’s been hugely encouraging to hear from such a broad range of independent music events who recognise the benefits of championing more female artists across their stages.
'Congratulations also to arts and music pioneer, Jayne Casey, our latest Keychange Inspiration award winner. I’m sure that the industry innovators and artists we’re supporting through the Keychange talent development programme will be inspired by people like Jayne. She demonstrated the importance of women’s contribution to music at a time when the gender gap was even greater than it is now.'
Rebecca Stewart of Cambridge Folk Festival added: 'Cambridge Folk Festival is delighted to be part of the Keychange initiative, especially as we currently aim for a 50:50 balance on the line-up and have done so for a number of years.
'We want to be held up as a shining example that this is possible and that if a folk festival can do it, then others can too. We hope it will inspire women to expect to be up there with the best and to keep fighting. And, as we are predominately a female managed festival, we want to show that women are as successful behind the scenes as well.'
For more information about Keychange, visit the website here.
