Sir Paul McCartney has likened Kanye West's song-making process to making a bowl of spaghetti.

The 75-year-old music legend teamed up with the 'Famous' rapper in 2005 when they released 'FourFive Seconds' alongside Rihanna, and he has revealed when the 40-year-old is working on a new track he takes ''little noodles'' of information he likes to put into the completed project.

Speaking to ABC in Australia, the 75-year-old said: ''I was sitting around with Kanye for a couple of days and I didn't think we'd written a song, because I was just playing around, noodling. I was expecting for an idea to come out there and then, but his way of working is he takes all these little noodles away and he makes spaghetti.

''He'll play with it and curate it and do this with it and get somebody else to do another bit.''

But McCartney has hinted he was shocked by the outcome of the track because he didn't know if his vocals were on the record at all as all he could hear was Rihanna.

H explained: '' So, it was months later when I got a track in the post and it was 'FourFiveSeconds' and I listened to it and it's Rihanna singing.

''I thought 'This is great, I love her singing it' but I had to ring up and say 'Am I on this?', you know. Yeah, they said 'You wrote all the guitar parts and that inspired us'. I said 'Okay, great thanks'.''