Still Tho and East of East: Atlantic Hip Hop Archive both disappear this Sunday at 5. Two levels; two deep-dive exhibitions; one price: free. Since Sep 21, the Mount Saint Vincent University Art Gallery has brought together two shows to explore the art of hip hop—the graffiti, the music, the people, the movement—and how it lends itself to groundbreaking forms of archival work and scholarship that honours hip hop’s ongoing 51-plus-year music, aesthetic and cultural legacy…