A little over a year since the Reynolds Center, where the Smithsonian American Art Museum and the National Portrait Gallery are housed, re-opened its doors, it continues to celebrate huge improvements to the building. This Sunday stop by for the grand opening of the Kogod Courtyard, which will include tons of musical performances both in the courtyard and inside on the third floor, hands-on activities for all ages (a Lite Brite station!), and, as usual,…