Seattle Art Museum’s collection of modern sculptures by notables like Tony Smith, Richard Serra and Louise Nevelson is about to get way bigger.

The rich get richer

Former president of Microsoft, Jon Shirley and his wife Kim, trustees at the museum, are donating their 48 works by sculptor Alexander Calder, estimated at $200 million.

Besides the donation of sculptures, the couple is also donating a $10 million endowment and another gift of up to half a million toward Calder research.

In a statement, Shirley tells what gave rise to his interest in Calder’s work.

“From the moment I bought my first work 35 years ago, I treasured the experience of living with Calder and from that point built my collection very intentionally.”

Even if you didn’t collect Calder, you’ve experienced his work if you ever had a hanging crib toy or singing wind chimes. Such household items were knockoffs of the artist's original idea.

And Calder first got his idea from watching fellow abstract artist Piet Mondrian paint squares. The sculptor thought the squares would look better if they moved around.

Calder was trained as a mechanical engineer and knew how to design metal shapes to move with the surrounding air. But even his static sculptures, called stabiles, suggest movement. Amoebic in shape, they seem to float.

Dazzling Albert Einstein

Maybe that’s why Albert Einstein saw Calder's "A Universe'' – a sculpture of moving spheres – reportedly stood transfixed before it for 40 minutes.

But the sculptor refused to call his creations art. He preferred the word "objects.'' That way, he said, he never had to defend it to those who didn't think it art.

The artist produced some 16,000 works, from sketches to monumental sculptures. By that count, he created a work a day for nearly 50 years.

Not that Calder kept to his studio. He was politically active and ended up on Nixon's enemy list for marching in Washington against the Vietnam War with his wife, Louisa James.

But the artist’s sculptures remain his claim to fame.

One of his works owned by the city of Grand Rapids, Michigan, became a city symbol.

And like all of his work, the one in Grand Rapids is abstract. This, even though he came from a family – mother, father, grandfather – who worked figuratively. His grandfather made the 37-foot-high statue of William Penn on top of City Hall in Philadelphia.

Why was abstraction his chosen style? According to his sister in the biography “Three Alexander Calders,” their parents and their artist friends were given to sketch nudes that hung in the family living room. “Sandy” was embarrassed as a teen when peers tittered at the nudes.

The donation of 48 Calder abstractions to the Seattle Art Museum will join a work he created in 1971 called “Eagle,” purchased by the institution with the help of Shirley and his first wife Mary in 2000.