Soul, funk, and gospel; solo acts and 17-person bands; backing singers striving for stardom and stars doing albums that are largely forgotten today. In the Seventies, Rolling Stone reviewed hundreds and hundreds of R&B albums — it was inevitable that some of them would be amazing but slip through the cracks of musical history, even LPs by the Supremes and the Jackson 5. These are 20 R&B discs that we loved, even if they've since been forgotten by most people outside the singers' immediate families.