What better way to spend your long holiday weekend than strolling around a downtown park and taking in some sidewalk art and great music? Chalk It Up!, a benefit for children’s arts education in the Sacramento region, is celebrating its 20th anniversary this year. Chalk It Up! features artists creating before your eyes more than 200 sidewalk paintings, which are then left on the sidewalk for the public to enjoy throughout the month of September. It will run from 10 a.m. to 6 p.m. Sept. 4 through 6 in Fremont Park at 16th and Q streets.