Darren Mueller examines how the advent of the long-playing record (LP) in 1948 revolutionized the recording and production of jazz in the 1950s. The LP's increased fidelity and playback capacity allowed lengthy compositions and extended improvisations to fit onto a single record, ushering in a period of artistic exploration. Despite these innovations, LP production became another site of negotiating the uneven power relations of a heavily segregated music industry. Exploring how musicians, producers, and other industry professionals navigated these dynamics, Mueller contends that the practice of making LPs significantly changed how jazz was created, heard, and understood in the 1950s and beyond. By attending to the details of audio production, he reveals how Black musicians such as Louis Armstrong, Miles Davis, Duke Ellington, and Charles Mingus worked to redefine prevailing notions of race and cultural difference within the United States. Mueller demonstrates that the LP emerges as a medium of sound and culture that maps onto the more expansive sonic terrain of Black modernity in the 1950s.