Conceptual artist Patrick Marold hit the big leagues last year when he was awarded a $1.5 million commission to create a work that will occupy the under-construction "valley" where the rail line will meet the new station and hotel at DIA. But even though Marold is adept at orchestrating massive works like these, he's also good on a more intimate scale, as he proved in Patrick Marold: Strata. Marold likes to use simple repeated shapes, like the cluster of metal rods that were used to create a standing sculpture, its shiny surfaces reflecting the room around it; or the rusted rods that were stacked precariously into a leaning pyramid. But he also uses ideas, which explains why his pieces are so smart.