Jay-Z and Kanye West are being sued by blues musician Syl Johnson, who claims that the duo unlawfully sampled one of his songs on their 2011 album Watch the Throne.

The Mississippi-based soul and blues singer alleges that The Joy, produced by West and Pete Rock and featuring Curtis Mayfield, used a sample of his 1967 song Different Strokes without permission. Johnson filed a complaint at the Illinois federal court on Friday.

Normally, an artist must either ask permission before sampling, pay the original artist royalties, or both. According to Johnson, West had wanted to use the song for the album My Beautiful Dark Twisted Fantasy, but after failing to obtain the rights to Different Strokes, knowingly and willfully used it for his project with Jay-Z instead.

Johnson's record label Numbero Uno Group is fully behind its client and prepared for a legal battle.

Two decades and several lawsuits later, Syl Johnson is a veteran of copyright infringement cases, and has done very well for himself clearing samples from his fertile catalog...for use in numerous tracks...Island Def Jam seems to think that Syl doesn't have any fight left in him. We're betting otherwise, the company said in a statement.

Different Strokes has been sampled more than 60 times in the past, by artists such as Wu-Tang Clan, Public Enemy, M.C. Hammer, N.W.A and the Geto Boys, according to WhoSample.com. Some of Johnson's other songs, such as Is it Because I'm Black and I Hate I Walked Away are also popular choices for hip hop producers.

Johnson unsuccessfully sued Cypress Hill for sampling Is it Because I'm Black in 1993 for the rap group's song Lock Down.

Listen to the The Joy and Different Strokes below.

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