Beyonce Knowles changes her email address every week, says singer Ed Sheeran, who collaborated with the pop star on his track "Perfect". "I have an email address I email (to get in touch with Beyonce). It actually changes every week. So I emailed that and we got on the phone, and it's been in the works since May," said Sheeran, reports femalefirst.co.uk.

ED Sheeran

Meanwhile, Sheeran was thrilled to get the songstress on the track, which is off his hit album "Divide", and enjoyed having her input on the backing track too. "Obviously she had twins (in June), and we finished (the song) in September, so I've been holding onto it since then ... The original version of 'Perfect' was just an acoustic guitar and she rung me up and was like, 'I don't know how you feel about this but I've taken all the instruments off it and it's just gonna be acoustic guitar," he said.

He added: "I was like, 'Ah that's great, because it used to be that!' Then when we got in together, it wasn't so much notes, it was very much like a back and forth thing, like, 'What'd you think of this?' Or 'What do you think of this?' and (we were) probably in the studio for four hours. She was just like, 'Right!' Went in, one take, came out, like, 'Yeah, that sounds alright!'"