Paul McCartney has joked he was "surprised" Michael Bublé didn't kick him out of the studio when he gave him some notes on their collaboration.

Bublé's new album, Higher, features three original songs and a bunch of cover tracks, including a reworking of McCartney's 2012 ballad My Valentine, which the former Beatle agreed to produce.

McCartney jokingly shared in an interview with Variety that he was surprised Bublé didn't boot him out of the studio when he suggested tweaks to his vocals.

"Michael invited me along to the session in New York suggesting I could help with producing it," he recalled. "So I went along and basically watched him work with a large orchestra and do the vocals. I was able to help him in small ways, suggesting that he sing certain phrases in certain ways, and to my surprise he didn't boot me off the session!"

However, the Canadian crooner never contemplated doing such a thing, as he found their collaboration to be "magic".

"He is who you wish he would be. He saunters into the studio alone. No group. No security. And he looked like he came in on a skateboard because he kind of floats when he walks. He wanted to be just a humble servant to the music," he praised.

The Haven't Met You Yet star believes Higher is the best record he's ever made. Regardless of how well it does critically or commercially, he already knows it is "successful" because the process of "making this record was my dream come true".

Higher was released on 25 March.