The Hootenanny Singers (for a couple of weeks originally called the Westbay Singers, Westbay English for Västervik) were a popular folk group from Sweden, founded in 1961, and continuing into the 1970s. The group included Björn Ulvaeus, who later was a member of ABBA. Other bandmembers were Johan Karlberg, Tony Rooth and Hansi Schwarz. The group was named "The Northern Lights" for an American-released LP in 1966.
In 1964 they debuted on the Swedish TV-show Hylands hörna with locally famous Swedish poet Dan Andersson's Jag väntar vid min mila (translated as "I'm Waiting at the Charcoal Kiln"). The song "Gabrielle" became an international hit song in 1964, translated and performed by the group in Swedish, German, Finnish, Italian, Dutch, and English. However they used the tune of the Russian song May There Always Be Sunshine by Arkady Ostrovsky, who was never credited because of political reasons.
The group's biggest hit was the 1967 Swedish language cover of the Tom Jones song "Green, Green Grass of Home" called "En sång en gång för längese'n" with Swedish lyrics by Stig Anderson.
Hansi Schwarz was also the leader of the Västervik folk ballad festival.