A veteran music executive has criticised the Grammy Awards in a full-page advert in the New York Times.
Steve Stoute said Grammy voters had "lost touch with contemporary popular culture" by snubbing artists like Eminem and Justin Bieber.
He added the show had become "a series of hypocrisies and contradictions", claiming both acts were only asked to perform to boost TV ratings.
Last week's ceremony attracted 27m viewers - the largest since 2001.
Stoute, who is most famous for managing hip-hop arts Nas, is the chief executive of marketing company Translation and is considered to be one of the most influential voices in entertainment marketing and pop culture.
He also took the National Academy of Recording Arts and Sciences to task for snubbing Eminem in 2001, which saw the rapper's Marshall Mathers LP miss out on album of the year in favour of Steely Dan.
Stoute's letter also questioned why Kanye West's Graduation was also passed over for the same award three years ago by Herbie Hancock's River: The Joni Letters.
"We must acknowledge the massive cultural impact of Eminem and Kanye West and how their music is shaping, influencing and defining the voice of a generation," Stoute wrote.
'Change this system'
Eminem, who led this year's Grammys with 10 nominations, picked up only two awards, while Bieber went home empty-handed despite his two nominations.
"How is it that Justin Bieber, an artist that defines what it means to be a modern artist, did not win best new artist?" Stoute said.
"His cultural impact and success are even more quantifiable if you factor in his YouTube and Vevo viewership."
Beiber lost out to singer and bassist Esperanza Spalding for the award in question.
Stoute added: "Interesting that the Grammys understands cultural relevance when it comes to using Eminem's, Kanye West's or Justin Bieber's name in the billing to ensure viewership and to deliver the all-too-important ratings for its advertisers."
He also said his "suspicions" over a link between performers and winners appeared to be proven true, citing Arcade Fire's surprise album of the year win just after they had finished performing on stage.
"Does the Grammys intentionally use artists for their celebrity, popularity and cultural appeal when they already know the winners and then program a show against this expectation?" he said.
He finished by calling on artists to "demand they change this system" and uphold "its mission for advocacy and support of artistry as culture evolves".