Personalized Dancing Rock On T-Shirt. Rock On in musical text with a happy dancing rock is a humorous music design. Fun gifts for back to school,marching band, birthdays, holidays and graduation. Everyone loves our Custom T-Shirts! Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.