Whether showcasing jazz or classical, rock or pop, 45 international music festivals pledged on Monday to work towards a common goal: achieving a 50/50 gender balance in their programming by the year 2022. The announcement comes amid increased publicity on the gender gap in the entertainment industry and renewed drives to close it.

The pledge, known as the Keychange initiative, was organized by the PRS Foundation, a UK music development charity.

"The Keychange network of female artists and industry professionals and the festival partners' idea of establishing a collective pledge will significantly accelerate change. I hope that this will be the start of a more balanced industry which will result in benefits for everyone," PRS CEO Vanessa Reed said at Monday's event.

Read more: Women underrepresented in the music industry?

A growing initiative

While some seven festivals had already committed to having an equal lineup of men and women, 35 additionally announced that they had signed on during the PRS Keychange event held at the Canadian High Commission in the United Kingdom.

Germany's Reeperbahn Festival in Hamburg, one of the initiative's founding partners, lauded the project:

"Reeperbahn Festival is proud to be a founding Keychange partner because we recognize the barriers that women are facing in the music industry," Reeperbahn's Founding Partner Alex Schulz said. "I hope that many more festivals will have joined with us by the end of this year, making this a global movement."

The other founding festival partners are BIME in Spain, Iceland Airways festival, Way Out West in Sweden, Musikcentrum Sweden, Tallinn Music Week in Estonia, MUTEK in Canada and The Great Escape in the UK.

The newcomer festivals pledging gender balance covered a broad range of musical tastes and locations, including the Katowice JazzArt Festival in Poland, North by North East music and technology festival in Canada, Norway's Borealis festival devoted to experimental music and Germany's Pop-Kultur festival in Berlin.

Read more: Women finding their place in jazz scene

Notably absent

While a few big names festivals signed on, such as the UK's premiere classical music festival, the BBC Proms, other major festivals remained absent, particularly those promoting rock music, which historically tends towards mostly-male lineups.

For instance, the British mega-music festival Glastonbury, which featured no women in its top three headliners last year, was not among the initiative's signatories. However, event co-organizer Emily Eaves is a Keychange ambassador who has expressed a desire to improving the festival's number of female performers. Other ambassadors include David Bowie producer Tony Visconti and Shirley Manson of the Scottish alt-rock band Garbage.

According to the PRS Foundation website, the Keychange initiative is supported by the Creative Europe program of the European Union, aiming at "empowering women to transform the future of the music industry." The foundation described the event at the Canada High Commission as "only the beginning" and said there are plans for an event at the European Parliament in Brussels later this year.