The 1962 letter written by Rolling Stones leader Brian Jones, inviting Charlie Watts to join the band, is to be auctioned in December with an expected value of $70-80,000.

The handwritten note has been kept by the late drummer’s family since he received it at his childhood home, while he worked in the advertising industry and played in Alexis Korner’s band Blues Incorporated.

When Jones posted it, the Stones hadn’t yet taken on the name they’d make famous; they were using a series of temporary drummers and hadn’t hired bassist Bill Wyman.

READ MORE: 15 Musicians Who Almost Joined the Rolling Stones

It took seven months for Watts to accept the invitation, and the definitive lineup – also featuring Mick Jagger, Keith Richards, and Ian Stewart – first played together on Feb. 2, 1963, at London’s Ealing Jazz Club.

“Dear Charlie, if you consider this letter rather impertinent, please excuse me,” it begins. “I don’t know at the moment what your relationship with Korner’s band is. … If you are not going to work with Alex in the future, and still want to play R&B, we are looking for a good drummer.

“Already we consider our band far better than Alex’s – we are getting a very tightly-knit sound. We are rehearsing on Mondays, Wednesdays, and Fridays. … [I]If you have time, let me know what’s happening.”

Where to See Brian Jones’ Letter to Charlie Watts

Jones signs off with the postscript: “If you are interested, our present line-up is 2 guitars, harp [harmonica], piano and drums. We are going to use a bass guitar eventually. Our present drummer is atrocious!”

Sotheby’s pop culture expert Craig Inciardi told the Guardian: “Few documents bring us as close to the formation of a legendary band as this letter.

“Written just weeks before the Rolling Stones’ first performance and months before Charlie Watts officially joined the group, it captures the excitement and ambition of a band on the cusp of history.”

The note will be on display in Sotheby’s New York from Dec. 2 until Dec. 8, with online bidding opening on the first day. The auction takes place on Dec. 15.