Personalized Trombone Santa Hat Robot Youth Long Sleeve T-Shirt. A robot wearing a Santa cap and holding a trombone is a funny gift design for low brass musicians, music teachers and school students in concert and marching band at Christmas time. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)