The work of great painters is typically thought to have come from the skill of their own hand. But for Sol LeWitt, the ideas behind the art mattered most, and those were to be shared, even replicated.

He would start with the basics: a line drawn in pencil; a series of shapes (a circle, triangle, trapezoid); or simple colors (red, yellow, blue, grey). And with the proper instructions these building blocks could be transformed into stunning, if at times bewildering, works of art by LeWitt or anyone else that decided to follow the directions.

(Narrated slideshow: Jock Reynolds, who directs the Yale University Art Gallery and who was a friend of LeWiit, talks about the artist's work and about the exhibition in this narrated slideshow of some of the wall paintings on display.)

The wall drawings of LeWitt, now on display at the Massachusetts Museum of Contemporary Art, show the evolution of styles across the artist's career: from refined, extremely structured and black and white to bold, full of color and a range of playful shapes. It is the first time these mural-sized works have been collected and given a permanent home.

A team of more than 50 assistants, local artists, interns and students executed the vast exhibit, following the detailed but often open-ended instructions left by LeWitt. Take for example the directions for Wall Drawing 46: "Vertical lines, not straight, not touching, covering the wall evenly." It gives instruction, but for those recreating the piece there remain decisions to be made in terms of the length and location of a line that keep alive the frustrations and excitement of creating a new work.

In that way, LeWitt worked as a painter and sculptor much like an architect or composer might not lay bricks or play music, but they create art nonetheless.

Reynolds also narrates this time lapse video showing the installation of the retrospective:

The exhibit, "Sol LeWitt: A Wall Drawing Retrospective," will remain on view for at least the next 25 years.