- Alexander Calder was one of the most innovative sculptors of the 20th century
- Artist is now the subject of two major exhibitions in London
- Alexander Calder: Performing Sculpture at the Tate Modern looks at his life's work
- The Calder Prize: 2005-2015 at Pace London brings together young artists who channel the artist's spirit in some way
London, England (CNN)Alexander S.C. Rower talks about his grandfather with the authority of a historian, the enthusiasm of a fan, and the charm of a silver-tongued dealer.