First recorded by Quincy Jones, with Minnie Ripperton, Leon Ware and Al Jarreau (R&B #74 1974).
Hit version by Average White Band (US #39/R&B #25 1975).
From the wiki: “‘If I Ever Lose This Heaven’ was co-written by Quincy Jones (‘It’s My Party‘), Leon Ware, and Bruce Fisher (‘You Are So Beautiful‘) for Quincy’s 1974 album, Body Heat. Ware, Minnie Riperton (whose 1975 album, Adventures in Paradise, Ware would produce and collaborate), and Al Jarreau were among the studio vocalists Jones used for the album.
“Average White Band recorded ‘If I Ever Lose This Heaven’ for their second album, Cut the Cake, released in 1975 (a recording that was plagued by creative and artistic differences, with several members of the band walking out of the studio on three occasions). Although not as groundbreaking as their debut album, AWB, the sophomore effort peaked at #5 on the Billboard Album Chart and #1 on the R&B Album chart along with yielding three hit singles: ‘Cut the Cake’ (US #10), ‘Schoolboy Crush’ (US #33), and ‘If I Ever Lose This Heaven’ (US #39).”
Average White Band, “If I Ever Lose This Heaven” (1975):