Skylark has certain artistic precedents in oversized pop art monuments, but here the non-referential aspect of the piece allows us to enjoy the gracious curved surfaces with semi-opalescent light. Held, seemingly tenuous on the curve of the tree, it has a bird-like lift, as referred to in its title. The clever engineering takes us from one full volume to an attenuated shaft . . . and then to another blossoming form above.