Betye Saar in front of a reproduction of a photographer of herself at Let's Get It On: The Wearable Art of Betye Saar (all photos Nereya Otieno/ Hyperallergic )LOS ANGELES — There is an African Adinkra symbol, “Sankofa,” that means “go back and get it.” Saar worked on the costumes for the play but also did the backgrounds; the wallpaper was her first foray into collage work. In fact, this entire exhibition is an ode to Saar discovering the practice of mixing media for which she would become internationally recognized. In her costume work, she reimagined second-hand clothes into abstract garments for the stage or gathered found materials to fashion into accessories. That idea is reminiscent of her classic assemblage work “Black Girl’s Window” (1969), made around the same era.