Eleanor Wachtel talks to American painter Frank Stella. Since the late 1950s he's been at the forefront of the art world, constantly pushing new ideas for abstract painting. He was the youngest artist ever to have a one man show at the Museum of Modern Art.  Frank Stella's latest project is a series of sculptures, or three-dimensional paintings, as he calls them - responding to the harpsichord sonatas of Domenico Scarlatti. They're vibrant and exciting pieces, the marks of an artist who shows no sign of slowing down. The works are on exhibit at the FreedmanArt gallery in New York until September 27th.