Though Johnson had been collecting art since his visit to the Bauhaus in Germany where he bought his first piece from Paul Klee, and often took his cues from his old friend Barr, Whitney’s influence increased with the passing years, according to the late MoMA Chief Curator Kirk Varnedoe. Initially employed as a designer at MoMA’s department of painting and sculpture, Whitney was plugged into the ’60s art scene with a later stint at Leo Castelli’s gallery and as an assistant to Jasper Johns. Warhol became a daily telephone confidant, and Whitney joined Claes Oldenburg in a performance piece. Starting in the 1970s, Whitney curated highly regarded solo shows for Johns, Cy Twombly, Willem de Kooning, David Salle and Eric Fischl.

With Whitney’s passion and perspective for collecting, the Painting Gallery was constructed in 1965. It was built into the side of a hill so that only its roof and massive  red sandstone entrance are visible. Three of Lynn Davis’ architecturally rich photographs from Burma, Syria and Yemen (1993–96) and Michael Heizer’s “Dragged Mass (Iso/Planar/Section)” (1983) hang in the wide entry hall. Whitney edited Davis’ book Monument, a further exploration of her iconic look at buildings and land forms. The three adjoining circular galleries have massive walls that are mounted like a giant poster rack; they are moved to view each painting. In correspondence with the National Trust in the 1980s, Johnson and Whitney envisioned a comprehensive timeline of Frank Stella’s painting and sculpture. This project anticipated a need to deaccession pieces by other artists.

Executive Director Christy MacLear notes that since that letter, several seminal works such as Warhol’s “S & H Green Stamps,” went to MoMA, but all Stellas from the early 1960s through 2005 were kept on-site, and though it’s unclear why plans changed, large-scale works by Salle, Cindy Sherman, Robert Rauschenberg and Julian Schnabel remain. (While these pieces are in the collection, they are not on view.) Annual reinstallation of the gallery will allow access to those works and to Warhol’s 1972 silkscreen portrait “Philip Johnson,” another example of the close ties between artists and collectors.

While the earth-berm Painting Gallery excludes natural light, the glass-roofed Sculpture Gallery exults in it. Built in 1970 and based on a series of squares rotated at 45-degree angles, the five-tiered space has wide display niches. Imposing works by John Chamberlain, George Segal, Robert Morris, Bruce Nauman and Andrew Lord can each be viewed in splendid isolation. Stella has four pieces, including “Raft of the Medusa, Part I” (1990), which acts as the gallery’s anchor. Both galleries reflect Johnson’s belief that artworks are best viewed individually. The roster of artists represented in these spaces further testifies to Whitney’s often prescient cultivation of talent. Lord is not alone when he says, “I miss David most when I’ve completed new work, when I’d like to show him what I’ve done, find out if I went off course.”

Johnson and Whitney were often among the first to bring new art to a wider audience. One of MoMA’s major benefactors, Johnson gave the museum Jasper Johns’ “Flag” (1954) and Warhol’s “Gold Marilyn Monroe,” the year it was made, 1962. In 1986, Johnson arranged for the Glass House estate to become part of the National Trust, but retained use until his death in 2005. Whitney, who died later that same year, served as a trustee at Houston’s Menil Collection and made a bequest to that institution that includes seminal works on paper by Johns. (Those works are on exhibit there until October 28.) Whitney also directed that his collection be auctioned and proceeds given to the National Trust to maintain the Glass House. The mix of American contemporary and folk art was sold by Sotheby’s for $13,802,452.

“Da Monsta,” the last structure Johnson designed on the site, is also the best example of his belief that art and architecture are one. The name, a Brooklynesque twist on the word “monster,” comes from the architect’s contention that the structure was almost animate. He regularly patted it like a pet when he passed it during his daily walks. Completed in 1995, it’s as much sculpture as it is building. Johnson used the term “structural warp” to describe the organic shape, which was inspired by an element of Frank Stella’s design for a Dresden museum. It’s fitting that Stella’s mixed-media “Shards I” (1986) hangs in its gently sloping cavernlike interior.