When producer Norman Granz held the first Jazz at the Philharmonic show on July 2, 1944, the notion that jazz constituted great American art wasn’t exactly commonplace: At best, it was popular entertainment; at worst, it was ghettoised as an extension of minstrelsy in a Jim Crow America where black expression was still trying to find its lane. Framed as a loose club jam brought to the concert hall stage, Granz’s series—the inaugural show of which featured a desegregated band including Les Paul, J.J. Johnson, Illinois Jacquet and Nat King Cole (billed, for contractual reasons, as “Shorty” Nadine)—helped recast jazz as “serious” music, as worthy of scrutiny and interpretation as avant-garde composition. It didn’t hurt that the vocabulary of jazz was, at the time, undergoing a transformation unto itself, shedding the formalities of big band and swing for the improvisatory wilds of bop. This shift, which mimicked similar departures in modernist painting and literature, is heard here on long, winding renditions of the standards "Oh, Lady Be Good" and "How High the Moon". (On the set's original issue on 78 RPM vinyl, each of these songs was split into three parts.) As much as JATP was a concert series, it was also an expression of social justice: Granz, who borrowed money to fund the first performance and its recording, insisted on integrated audiences and ensured equal accommodations for all musicians. Additionally, this inaugural show’s proceeds were donated to the 17 wrongly accused Latino defendants of the Sleepy Lagoon trial—a racially charged precursor to the Zoot Suit Riots, and a moment when jazz aligned itself with the overtures of the civil rights movement.