A $13 million national blues museum’s debut in downtown Saint Louis is now scheduled for next spring. The site’s executive director, Dion Brown, tells the Saint Louis Post-Dispatch that the grand opening is next April 2^nd, allowing for various exhibit cases for the 23,000-square-foot museum to be shipped from Seattle.  Brown says the museum has roughly 16,000 feet of exhibit space is largely complete, with staffers doing test runs of interactive elements.  Brown became the museum’s chief earlier this year.  He previously had been executive director of the B.B. King Museum and Delta Interpretive Center in Indianola, Mississippi.