Hard to top the eclectic line-up at CUSP Vol. 4: Jeremi Johnson, aka 10th Letter, is an Atlanta-based Afro-futurist who combines visual arts with electronics, found sounds and live instrumentation to create an experimental experience. Ghost Trees is, of course, Charlotte’s premiere free-jazz outfit. And Quisol is a relative newcomer to the scene, blending Latin- and jazz-tinged music with a provocative, activist zeal. Also on the bill: the dark tones of Brother Aten and whimsical sounds of Zodiac Lovers.