Personalized Shamrock Music Notes Youth T-Shirt. A shamrock comprised of green music notes is a fun design for family and friends during the March holiday of St. Patrick's Day and Celtic festivals. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.