Rush was left-handed and played as such; however, his guitars were strung with the low E string at the bottom, upside-down from typical guitarists. He often played with the little finger of his pick hand curled under the low E for positioning. It is widely believed that this contributed to his distinctive sound. He had a wide-ranging, powerful tenor voice.
Rush moved to Chicago, Illinois, in 1948/49 and, after being inspired by Muddy Waters, made a name for himself playing in blues clubs on the South and West Side of the city. During this period he formed his own group, initially under the name Little Otis. From 1956 to 1958, he recorded for the independent label Cobra Records and released eight singles, some featuring Ike Turner or Jody Williams on guitar. His first single, “I Can’t Quit You Baby”, in 1956 reached number 6 on the Billboard R&B chart. During his tenure with Cobra, he recorded some of his best-known songs, such as “Double Trouble” and “All Your Love (I Miss Loving).”