The Menil Collection show Dear John & Dominique covers roughly half a century of correspondence between the de Menils and some of the brightest luminaries in modernism — ranging from early dadaists and surrealists like Max Ernst all the way through Renzo Piano, whose Shard tower in London topped off just in time for the 2012 Summer Games.

While it's amazing to read letters penned by Dorothea Tanning and see notes signed "Bob Rauschenberg," a particular pair of letters between John de Menil and Philip Johnson offers a perfect example of the intimate working relationships the de Menils established with their clients and friends as they forged one of the art world's most highly-regarded collections.

The correspondence takes place in October 1962, more than a decade after Johnson designed the Menil's groundbreaking modern home in Houston. The architect's career is thriving after the success of the Seagram Building and the Museum of Modern Art sculpture garden. In spite of the public successes, de Menil feels little need to hold back his thoughts about Johnson's recent work.

"This is a turning point in modern architecture," he writes. "Now you are at grips with that baby you have conceived and it proves to be a tough baby. In some instances, your clients do not give you the freedom to let him breath . . .

"In others, it looks as if you were afraid to go all the way . . . In other instances, I just don't understand."

De Menil takes issue with one of Johnson's most recognized buildings, the New York State Theater at Lincoln Center, while praising one of the architect's least known projects — a nuclear reactor in Israel.

But Johnson's response speaks volumes of the de Menil's influence in postwar American art and architecture.

The architect is ecstatic for the comments, writing, "I've been waiting for your good criticisms for years. I have felt for some time that you had these points welling up in you." He goes on to call his projects for Yale University his best work to date, while taking a jab at fellow designer (and architecture Yale dean) Paul Rudolph.

To say the least, it's a rare and shockingly candid moment in art history . . . and just one of the many in the exhibition, including a silkscreen Andy Warhol presented to Dominique upon John's death in 1973 as well as a letter from sculptor Jim Love encouraging the patroness to act on her dreams of building a museum to house the de Menil collection.

After making your way through the exhibit, grab a map for the Voices of the Menil audio tour, which offers an historically-minded stroll through the "neighborhood of art" in celebration of the Menil's 25th anniversary. A wonderful compliment to the archival letters, the cellphone-led walk covers 17 sites using rare audio clips from John and Dominique themselves, as well as sound bites from Renzo Piano and artist Max Neuhaus.

Organized by Menil archivist Geraldine Aramanda and museum curator Michelle White, Dear John & Dominique will be on view through Jan. 6, 2013.