The Beatles would go on to make some of rock's greatest records at Abbey Road Studios, but when the band filed into the building for their first session there on June 6, 1962, they were still a long way from the Fab Four who'd soon conquer the charts.

In fact, as engineer Norman Smith later bluntly told Sound on Sound, the young quartet "didn't make a very good impression, apart from visually." They brought their own gear, which didn't help, proving woefully under-powered for Smith's purposes. "They had tiny little Vox amplifiers and speakers, which didn't create much of a sound at source," he explained. "I got nothing out of the Beatles' equipment except for a load of noise, hum and goodness-knows-what."

The band's underwhelming first impression was a major problem, considering they'd been brought in for a test session by EMI producer and A&R exec George Martin. With their budding career at stake and facing a lack of other options, they needed to prove they were a worthwhile investment — unfortunately, at first blush, Smith said he "heard nothing" that would indicate they were remarkable songwriters or interpreters.

Equipment difficulties aside, Smith finally heard something when the Beatles played "Love Me Do," and summoned Martin in to take over for producer Ron Richards, who'd been supervising in his stead. For Martin to personally involve himself in test sessions was abnormal — and he was known as more of a comedy producer at the time — so when he walked in, Smith later recalled thinking, "This must be some kind of special artist test for him to show up." By the end of the day, both men felt they'd heard the start of something with real potential, but Martin was under no illusions about how far the group needed to go before they were ready for the spotlight — and he let them know it in no uncertain terms.

"He gave them a long lecture about their equipment and what would have to be done about it if they were to become recording artists. They didn’t say a word, they didn’t even nod their heads in agreement," said Smith. "When he finished, George said, ‘Look, I’ve laid into you for quite a time, you haven’t responded. Is there anything you don’t like?’ I remember they all looked at each other for a long while, shuffling their feet, then George Harrison took a long look at George and said ‘Yeah, I don’t like your tie!’ That cracked the ice for us."

Unfortunately for one member of the Beatles, it wasn't just their equipment Martin thought needed to change. Speaking with manager Brian Epstein, Martin pinpointed drummer Pete Best as the Beatles' weak link, and said he'd be bringing in a studio replacement for future sessions. After Epstein conferred with the other members of the group, the writing was on the wall for Best, who was fired by the end of the summer and replaced with Ringo Starr.

The rest was rock 'n' roll history. And it all started with Martin's willingness to take a gamble — and Smith's ability to listen past the Beatles' early rough edges to hear something special, even if he wasn't quite sure what it was.

"They left, and George turned to me and said, 'Well, what do you think?' And I said, 'I've seen a lot of groups come in for artists test, but this one — there is something special about them. I can't tell you what, but there is something there,'" Smith recalled. "The test hadn't gone too well, and I wasn't impressed by their sound. But they had an appealing quality, a kind of charisma."

Beatles Albums Ranked Worst to Best