In the Slot came off a four-year string of classic singles and albums. As Bump City era lead singer Rick Stevens exited, the phenomenal Lenny Williams replaced him. With Williams, Tower of Power became a hit-making machine as albums like Back to Oakland and Urban Renewal became R&B standards. In the Slot marks the first album of vocalist Hubert Tubbs. He possessed a throaty more muscular voice a few shades lower than his predecessor. While it was serviceable, Tubbs' voice didn't have the same grace and agility as Williams'.