The album cover was a commercial invention that became an art form, and the story of how that happened is also the story of how music became visual.

Alex Steinweiss, hired by Columbia Records in 1939, reportedly made the first argument that illustrated covers might sell more records. By the 1960s, the cover was doing things that went beyond commercial function. The Beatles’ Sgt. Pepper sleeve treated the album as a complete artifact. Pink Floyd worked with Hipgnosis on covers that operated more like conceptual art than marketing. Blue Note Records built a visual identity so coherent it functioned as a brand across releases that had nothing else in common.

The CD era compressed covers into smaller squares. Digital streaming threatened to reduce them to thumbnails. What actually happened was more interesting: artists and designers responded by making covers that worked at thumbnail size but rewarded closer attention, and by investing more in physical vinyl packaging than they had in years.

Brat’s chartreuse rectangle, the stark photography on Kendrick Lamar’s To Pimp a Butterfly, the visual world Beyonce built around Lemonade. Contemporary artists still understand that the cover is the first thing you see and the thing you remember. That has been true since 1939.