Note to Tireswing Theatre: TURN DOWN THE VOLUME! Shrieking doesn't make lines funny, it makes them piercing and incomprehensible. There are good things in writer-director Tami Zimmerman Henry's family-oriented production, which looks at both Leonardo's life and his literary efforts: not all of it's loud. Fourteen-year-old Pippin Mueller is deft as the artist's hummingbird model, and occasionally the fables earn a laugh, as when Maggie Graham plays a balky camel and Rick Smith a frustrated camel driver. But at 100 minutes the show is too long: Henry has included far too many stories, often seemingly unrelated to the Leonardo plot. It doesn't help that sometimes neither the text nor the costuming tells us what beast or plant we're watching. Through 6/11: Fri 8 PM, Sat 5 and 8 PM, Sun 3 PM, Athenaeum Theatre, first-floor studio theater, 2936 N. Southport, 312-902-1500, $10-$15.