MAASTRICHT, THE NETHERLANDS — The Dutch violinist André Rieu, known by many as the “King of the Waltz,” is constructing what looks like the garden of a monk’s cloister, with marble arches and sandstone arcades, next to his 17th-century castle here. The only things missing are the monks.

What else to do with the millions this classical musician for the masses earns every year with his hit worldwide concert touring act and his best-selling albums and concert films?

The superstar violinist, 67, has sold 40 million CDs worldwide, and his tours, featuring popular favorites like “The Blue Danube” waltz and the theme from “The Godfather,” have outsold Janet Jackson, Fleetwood Mac and Beyoncé, according to Billboard. His orchestral tour in Europe and Latin America from June to October 2015 had $19.1 million in ticket sales.

His son Pierre Rieu recently gave a tour of the family’s home and gardens while Mr. Rieu was away on an Australian concert tour. He said the cloister, part of a complex that includes father and son homes and three guesthouses, was inspired by the family’s yearly trips to Rome. “André was always very impressed by these structures,” he said, “and he decided to build one of his own.”

André Rieu performs about 100 concerts a year with his 55-piece Johann Strauss Orchestra, often in stadiums filled with tens of thousands of swooning (and sometimes waltzing) fans, who are typically gray-haired and mostly women.

His new album, “Falling in Love,” released on Nov. 25, has reached No. 7 on the British CD charts and has bolstered sales for his holiday tour there. He also had two popular concert movies this year, with more than 2.5 million pounds, about 3 million euros, in ticket sales with “André Rieu’s 2016 Maastricht Concert” in July and “André Rieu: Christmas with André” in November, according to CinemaLive, the films’ distributor. “Christmas with André” played in 480 theaters in Britain and Ireland on Nov. 19, and 290 theaters on Nov. 27, CinemaLive said.