Nile Rodgers, Kenneth “Babyface” Edmonds, Greg Kurstin, Frank Dukes, Benj Pasel and Justin Paul, Mike Elizondo, Murda Beatz, Ross Golan and Teddy Geiger — who between them have collaborated with everyone from David Bowie and Aretha Franklin to Adele and Camila Cabello — are among the dozens of songwriters who slammed Spotify in an open letter released today over the streaming giant’s appeal of the Copyright Royalty Board’s decision to increase royalty rates for songwriters.

While Amazon, Google and SiriusXM/Pandora also joined the appeal — which challenges the Copyright Royalty Board’s decision to increase the compulsory mechanical rates paid to songwriters by 44% over the next five years — the songwriters singled out Spotify, as it has attempted to deflect criticism over the appeal by mentioning its “Secret Genius” programs and awards, which are intended to promote songwriters, producers, engineers and other less-recognized people behind hit songs.

“We’re hurt and disappointed,” the songwriters wrote in the letter, which was addressed to Spotify chief Daniel Ek and posted on social media. “You created a songwriter relations team and ingratiated Spotify into our community. We know that you are not the only DSP appealing the Copyright Royalty Board (CRB) rate determination. You are, however, the only provider that made us feel we were working to build a modern music industry together.

“Now, we can see the real reason for your songwriter outreach. You have used us and tried to divide us but we stand together,” the letter continues. “Our fight is for all songwriters: those struggling to build their career, those in the middle class and those few who have reached your Secret Genius level. But none of us are ‘secret!’ WE all create the ONE thing you sell… songs.

“Do the right thing and drop your appeal of the Copyright Royalty Board rate determination,” it concludes, before signing off as the “Not So Secret Geniuses.”

Read the letter in full below; a rep for Spotify did not immediately respond to Variety‘s request for comment.