Art and music are considered ECAs (extra-curricular activities). You would get some credit but, honestly, not much for an art display. If you've been active in the local arts and can use your experience to demonstrate leadership, it would be more useful for USNA purposes.
If your passion is art, USNA may not be for you. There really isn't much, if any, opportunity to pursue it while at USNA or in the USN/USMC. Not saying art isn't important but it's not really important or needed in the military.
There are more options for music. USNA has a number of musical activities, including Drum & Bugle Corps, Pipes & Drums, a number of choirs and glee clubs, etc.