Everyone knows that Frank Sinatra was a blue-eyed crooner and dapper member of the “Rat Pac.” But did you know he was also an artist, and a prolific one at that?

Next month, Sotheby’s New York will auction eight of the singer’s paintings, most of which were completed in 1991 at the Palm Springs estate in Rancho Mirage dubbed “The Compound,” where Frank and his fourth and final wife, Barbara, spent most of their relationship.

The paintings vary dramatically in style, but most are abstract compositions with geometric shapes and bright colors. One appears to riff on Mondrian’s famous primary-color ode to New York, Broadway Boogie Woogie (1942/3). One curious departure is a painting of a primitive-looking white face floating on a blue background—offered in the sale in two forms. Reportedly, Sinatra made these “self-portraits as a clown” as a way to cope with the breakup of his tempestuous marriage to Ava Gardner.

Frank Sinatra’s Yarmulke and U.S. Drinking Team Jacket. Courtesy of Sotheby’s.

The sale also includes more than 130 works of fine and decorative art, jewelry, and other memorabilia that Frank and Barbara Sinatra collected over 22 years. The eclectic offerings from the estate include a hand-crocheted yarmulke, a blue satin jacket embroidered with “U.S. Drinking Team” and “Coach” appliques (just$300-500), various Fabergé-designed trinkets, and the 20.6-carat diamond engagement ring he gave to Barbara in a glass of champagne.

Frank Sinatra, Untitled (1991). Courtesy of Sotheby’s.

According to the artnet Price Database, Sinatra’s work has come up for auction 39 times between October 1990 and November 2017, mostly selling at prices safely within their estimates. One aberration was a 2016 sale from the collection of Ronald and Nancy Reagan, where a painting Sinatra gave to to the first lady for her birthday fetched $223,500—shattering its presale high-estimate of $8,000.

“Lady Blue Eyes: Property of Barbara and Frank Sinatra” will take place on December 6, 2018 at Sotheby’s New York. See more examples of Sinatra’s paintings below.

Frank Sinatra, Untitled (1990). Courtesy of Sotheby’s.

Frank Sinatra, Untitled (1986). Courtesy of Sotheby’s.

Frank Sinatra, Untitled (1991). Courtesy of Sotheby’s.

Frank Sinatra, Untitled (1989). Courtesy of Sotheby’s.

Frank Sinatra, Untitled (1990). Courtesy of Sotheby’s.

Frank Sinatra, Untitled (1991). Courtesy of Sotheby’s.