Unless you're a student of jazz, you've probably never heard of one of its key prototypes, Charles Joseph "Buddy" Bolden, a powerhouse cornetist known as a pioneer of New Orleans ragtime by modern academics and as the leader of one of the hottest bands in town by his contemporaries. His celebrated but brief career ended in 1907, when "King Bolden" was laid low by schizophrenia and institutionalized for the rest of his life. Much of what we know of him today comes from oral history mingled liberally with mythology. This is rich terrain for John Akomfrah, a British artist and filmmaker of Ghanaian descent who is internationally renowned for his work on postcolonial ethics, memory, and identity. Precarity, Akomfrah's new three-channel video installation at the Nasher, is "as much a ghost story as it is a portrait of a historical figure," writes curator Trevor Schoonmaker; it's also a portrait of a city that knows a thing or two about achievement and erasure. Part film essay, part historical documentary, and part something else, Precarity runs at the Nasher through August 26; Akomfrah gives the annual Rothschild Lecture on April 19.