Freddie Mercury will go down as one of the greatest vocalists of all time, but during a recent interview Brian May admitted that Queen was unsure about him when they first joined forces in 1970.

“When we first worked with him, it was a little unnerving,” the guitarist confessed. “Because he did a lot of running around the place and screaming his head off. So we thought, ‘Is this going work?’”

“And not everybody liked him, I’ve got to say. A lot of people found him kind of abrasive – but they all thought he was interesting and entertaining. At that point, though, he wasn’t the singer that we all got to know as Freddie Mercury,” he added before recalling Queen’s time in the studio to record their first demo in 1971.

“We went into the studio, and… as soon as Freddie heard his voice coming back, he went, ‘Oh, I don’t like it. I’m gonna do that again,'” May explained. “And he would go back and back and back, until he got it the way he wanted it. So he became, instantly, very aware of what he sounded like, and incredibly quickly fashioned himself into the singer he wanted to be.”

But that wasn’t the end of it. Mercury was always trying to better himself, even when Queen was hugely successful. “It probably went on forever. Every time we were going to make a new album, Freddie would push himself further,” May pointed out. “He would hear himself come back, and he would say, ‘No, I want to do better, longer, more passion, more –’ whatever it was… He was always looking for new textures, and looking to get more out of himself.”