The Flying Pickets, Only You, 1983. In 1980 Vince Clarke was going through two divorces, one with his wife and one with Depeche Mode. It's not known which divorce inspired Only You, but when Clarke's former band declined to record it, he brought the track with him to Yaz/Yazoo. As the new band's first release, in 1982 he and vocalist Alison Moyet took it to #2 in the UK and #67 in America, where the single's b-side, Situation, was also released separately as a 12", hitting #1 on Billboard's dance chart. The following year British acapella group The Flying Pickets (whose name indicated support for England's striking miners) covered Only You, taking it to #1 for five weeks in the UK, where it remains a Christmas-time radio classic. In 1984 the group returned to the UK Top Ten with an acapella cover of the Marvelette's 1967 smash When You're Young And In Love, but the act never had another hit. The Flying Pickets' Only You remains the UK's only acapella #1 hit single. Bobby McFerrin's 1988 single Don't Worry, Be Happy is the only such song to reach #1 in the states, but purists point out that McFerrin's track employs multiple overdubbings and cannot be performed live. Only You has been covered by many other artists, including Judy Collins, Rita Coolidge, and Enrique Inglesias. My favorite version is the one below. Dig the groovy hairstyles.
CORRECTION!: Sharp readers point out that the Housemartins' 1986 acapella cover of the Isley Brothers' Caravan Of Love also reached #1 in the UK - something not mentioned on the recap of acapella hit singles I used for this post. D'oh!