Sound and touch devices will be available at public gatherings on April 8, when a total solar eclipse crosses North America, the moon blotting out the sun for a few minutes. On eclipse day, students at the Texas School for the Blind and Visually Impaired plan to sit outside in the school’s grassy quad and listen to a small device called a LightSound box that translates changing light into sounds. When the sun is bright, there will be high, delicate flute notes.