Three Piece Sculpture: Vertebrae follows Moore’s two and three piece reclining figures of 1959-63, but has more in common with his abstract multi-part sculptures from the 1930s.[1] Here, the focus is on the relationship between the forms and the way they interact to create a unified whole. 
 

Although the overall impression is highly abstract, the work’s title and the easy organic harmony between the forms alludes to their origins. It is likely that the forms were inspired by a bone or piece of flint in Moore’s maquette studio, and, like vertebrae, the forms share the same basic shape but are not identical. Their arrangement too recalls a spine; the massive forms interlock in a horizontal, rhythmic, row. The two end pieces mirror each other, their angular uprights leaning towards the connecting piece between them. Talking about his two and three piece reclining figures in 1963, Moore said: ‘… one could have gone on and made a four- or five-piece, like a snake carrying through with its vertebrae.’[2] It is easy to imagine that these three forms are just part of a larger whole, a giant spine at rest. 
 

Moore was fascinated by interlocking forms, and explored them in several other sculptures including Locking Piece 1963-64 (LH 515).[3] Both Locking Piece and Three Piece Sculpture: Vertebrae convey a dense, muscular power, but their execution is very different. In Locking Piece, the energy is concentrated around a central hole, while in this work a dynamic force is implied by the lateral interplay of monumental forms. Unlike the subtly textured surface of Locking Piece, Three Piece Sculpture: Vertebrae is smooth and polished, a finish which serves to amplify the tension in the forms.

Three Piece Sculpture: Vertebrae was one of the last large works made using an internal wooden armature, which was draped in scrim (a bandage-like fabric) and then covered with successive layers of wet plaster. In 1968, Moore began to experiment with polystyrene, and soon found that it had many advantages over plaster. He explained, ‘… a single form of the ‘vertebrae’ would need three of us to move it round. I can move polystyrene alone, the material is so light.’[4] Polystyrene was also easily worked with a hot wire cutter and less easily damaged than plaster which was prone to cracking.

Realised in four scales, Three Piece Sculpture: Vertebrae was preceded by a maquette (LH 578) and working model (LH 579), and followed by Three Forms Vertebrae 1978-79 (LH 580a) in which the parts have almost doubled in size. The largest iteration was commissioned by the city of Dallas for the plaza outside their new city hall, designed by I.M. Pei and completed in 1978. Moore and Pei were already good friends, having previously collaborated on The Arch (LH 503b) for Pei’s new public library in Columbus, and Mirror Knife Edge (LH 714) for the extension of the National Gallery of Art in Washington DC. When Moore saw the city hall – a striking inverted pyramid in glass and concrete - he realised that his work would need to act as a counterpoint to the building’s crisp angularity. Three Piece Sculpture: Vertebrae would work, he thought, but would need to be much bigger, and the parts rearranged so that people could walk between them.

In early December 1978, the huge forms of Three Forms Vertebrae were installed on the plaza, overseen by Moore and Pei, and accompanied by a great deal of public interest. When Moore saw the sculpture in its final position he said: ‘It looks like some kind of giant animal. It looks like a whale coming out of the water.’[5]