Veteran singer/songwriter Michael Mcdonald has urged rapper Kanye West to learn to play an instrument and write "two bars of valid music" before criticising Beck's Grammy win.

West stormed the stage at the recent Grammy Awards to protest as Beck picked up the Best Album prize, and he later declared Beyonce was the more deserving winner and ordered the prolific musician to hand the trophy over to the pop singer.

The hip-hop star has now come under fire from Doobie Brothers legend MCDonald, who insists West has no right to criticise Beck because rapping over a computer-generated backing track does not make him an expert on music.

He tells Ultimate Classic Rock, "It's pretty obvious what Kanye's problem is. When Kanye gets to a point where he can actually put a couple of notes together either vocally or two bars of valid music playing an instrument, then he might have a right to criticise somebody else. Until then, I think he's just talking to hear the sound of his own voice.

"The whole kinda cut-and-paste thing is a certain kind of art form all by itself. I don't know if I call it songwriting from a musician's standpoint... Beck is obviously a consummate musician. He plays instruments, many instruments. He can make his own record without having a fleet of computer operators onboard."