When Iron Maiden started out, they were a different beast than the one they eventually became. Though bassist and founder Steve Harris cringes at the mere mention of it, the band had the spirit and energy reflected in the punk movement. And original singer Paul Di'Anno had a gruffer, working-class spit -- more so than most Robert Plant imitators of the day.

Di'Anno's style was crucial to Iron's Maiden initial sound and style, but his tenure wouldn't last long. The band was formed in 1975, with Di'Anno coming on board three years later. Their self-titled debut was issued in 1980, with the classic Killers following the next year. In September 1981, Di'Anno was booted from the group and former Samson singer Bruce Dickinson was brought in. As the story goes, Di'Anno was ushered out because his vocal abilities weren't up to par with how Harris thought the band should sound.

There were also rumors of drug abuse, but Di'Anno remembers it differently. "I left Iron Maiden because they were going too heavy metal, and Iron Maiden is a money-making machine, and I don’t give a f--- about it," he told an interviewer in 2013. "It was not about drugs. It was nothing like that." Though Di'Anno quickly added, "But you need to take drugs when you’re with Iron Maiden because they’re so f---ing boring. And the only drugs were aspirin, because Steve -- F---in’ headache."

When discussing the band's first recordings with Metal Thunder Radio, Di'Anno noted that Harris "had most of the words and the lyrics all written. That was some of the bones of contention that we had in the band — that I didn't get to write as much as I wanted to. 'Cause I am actually quite a prolific writer, but a lot of my songs were not accepted. 'Cause it's Steve's band, obviously. I’m telling you. Iron Maiden is Steve Harris’ band ... and all it is is money, money, money, money – nobody else counts."

In a 1981 interview, Harris was far more diplomatic about the situation. "The first two albums were the songs that were written over the four-year period before we were signed," he said. "I think it's probably more down to the songs than Paul's voice, really. I thought Paul had a really good voice, but there's no way we could have carried on with Paul because he didn't want to do touring and that anyway. We had to make a change. If we didn't make a change, I think maybe the band would have split up or something. I don't think that Maiden would still be here if we'd have stayed with Paul."

Di'Anno made his last appearance with Iron Maiden on Sept. 10, 1981, along with the official announcement of his departure and the arrival of new singer Dickinson. "I'm a punk musician, a punk singer," said Di'Anno. "But I can do heavy metal better than most heavy metal singers."

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