For many people, rock's primal scene is set in a recording studio, in Memphis, in 1954. There, three musicians (Scotty Moore, Bill Black and Elvis Presley), a producer/engineer (Sam Phillips) and a tape recorder (Ampex) create a song ('All Right Mama') that durably transforms the physiognomy of music. In this article, I examine the technological, political and intellectual circumstances that made this event possible. One word holds pride of place in my discussion: feedback, a mode of organisation that originated in British scientific laboratories of the eighteenth century. 2 1 A great " thank you " to my sciences studies' mentors Jean-Paul Gaudillière and Ilana Löwy, to Valentine Lellouche for the drawing and to Illa Carrillo Rodríguez for the translation and (good) comments. 2 My approach is not exclusive and is compatible with the literature that attributes Elvis Presley's sudden emergence in the music scene to economic factors [Peterson 1991], to the audience's weariness of crooners [Ward 1986] or, indeed, to Presley's and his producer's talent