It takes a great client to make a great building, as architects like to say when they’re feeling modest. One of the major patrons of the 20th century put it this way: “Great architecture is ... a triple achievement. It is the solving of a concrete problem. It is the free expression of the architect himself. And it is an inspired and intuitive expression of his client.” Those were the words of J. Irwin Miller, whose elegant Modernist house by Eero Saarinen, built in 1957 in Columbus, Indiana, opened to the public for the first time in May. Since then, tours of the house have been booked solid and are sold-out through August.