NEW YORK (AP) — The Beatles’ first recording contract was signed in Hamburg, Germany, where the band honed its craft playing gigs in the city’s boisterous nightclub district.

The 1961 recording session produced the single “My Bonnie.” It was released on the Polydor label in Germany only and never hit the top charts. But the tune led directly to the Beatles’ discovery back home, a contract with EMI the following year and their first hit, “Love Me Do.”

Heritage Auctions will auction the six-page contract in New York on Sept. 19 for an estimated $150,000. It’s the centerpiece of a Beatles collection spanning the band’s entire career. It’s being sold by the estate of Uwe Blaschke, a German graphic designer and noted Beatles historian who died in 2010.

“Not many people know that the Beatles started their careers in Germany,” said Beatles expert Ulf Kruger. “The Beatles had their longest stint in a club in Hamburg at the Top Ten Club. They played there three months in a row, every night. The style they invented in Liverpool, they cultivated in Hamburg.”

“Without this contract all of the pieces wouldn’t have fallen into place,” added Dean Harmeyer, Heritage Auction’s consignment director for music memorabilia.