More than 1,000 artists have signed a letter echoing calls for Europe’s leaders to address the value gap that exists between digital music consumption and revenues returned by user-generated services like YouTube.

It’s the latest in a fast-growing pile of criticism being slung at the Google-owned platform by artists, rights holders and music companies objecting to what they view as disproportionate returns for the commercial exploitation of music.

In the past month alone, fifty-eight members of the European Parliament petitioned the European Commission (EC) over safe harbor provisions, while Paris-based International Artist Organisation (IAO) called for legislative action to address the "value gap."

June has also brought the publication of a print ad calling for reform of the Digital Millennium Copyright Act (DMCA) -- the U.S. law which contains safe harbor provisions -- coordinated by manager Irving Azoff and which featured Taylor Swift, Paul McCartney, Carole King among its 180 signatories.

Earlier in the year, Katy Perry, Christina Aguilera, Lionel Richie, DeadMau5, Garth Brooks and Jon Bon Jovi were among hundreds of signatories of a petition addressed to the U.S. Copyright Office for similar legislative reforms that, they say, are essential "to bring about balance."

“This is a pivotal moment for music. Consumption is exploding. Fans are listening to more music than ever before. Consumers have unprecedented opportunities to access the music they love, whenever and wherever they want to do so. But the future is jeopardised by a substantial ‘value gap’ caused by user upload services such as Google’s YouTube that are unfairly siphoning value away from the music community and its artists and songwriters,” reads the latest letter, which is signed by ABBA, Coldplay, The 1975, Paul Weller, David Guetta, deadmau5, James Bay, Mark Ronson, Maroon 5, Robin Schulz, among many others, and is addressed to European Commission President Jean-Claude Juncker.

“This situation is not just harming today’s recording artists and songwriters. It threatens the survival of the next generation of creators too, and the viability and the diversity of their work,” warns the letter, which was co-ordinated by music trade bodies IFPI and IMPALA.

“The value gap undermines the rights and revenues of those who create, invest in and own music, and distorts the market place,” it goes on to say, noting that safe harbour provisions were passed two decades ago to help develop nascent digital start-ups but are today “misapplied to corporations that distribute and monetise our works.”

The letter concludes by urging the European Commission to “fix this profound market distortion” by clarifying the appropriate use of safe harbour provisions in its forthcoming review of copyright legislation, due to be published this fall.

Two weeks ago, YouTube responded to criticisms from Trent Reznor and Nikki Sixx over the same issue, writing that "the overwhelming majority of labels and publishers have licensing agreements in place with YouTube to leave fan videos up on the platform and earn revenue from them," the statement reads. "Today the revenue from fan uploaded content accounts for roughly 50 percent of the music industry’s YouTube revenue. Any assertion that this content is largely unlicensed is false. To date, we have paid out over $3 billion to the music industry -- and that number is growing year on year."