Siw “Siwan” Gunnel Margareta Malmkvist (born 31 December 1936) is a Swedish singer who has been popular in Scandinavia and Germany. She had a number one hit in West Germany in 1964 with “Liebeskummer lohnt sich nicht” (English: “Lovesickness Is Not Worthwhile”), and on 18 July 1964 she became the first Swede to have a hit on the US Billboard Hot 100 chart, when “Sole Sole Sole”, a duet with Italian singer Umberto Marcato, entered the chart, peaking at #58.
Having had some 40 hits on Swedish radio chart Svensktoppen and 20 on the German singles chart, she has altogether recorded about 600 songs (and has made recordings in ten different languages: Swedish, Danish, Norwegian, Finnish, Dutch, German, English, French, Italian and Spanish) throughout the past five decades, which makes her one of the most productive and successful Swedish female singers.
Malmkvist has been a contestant in the Swedish Melodifestivalen several times, most recently in 2004 together with Towa Carson and Ann-Louise hanson, singing the song “C’ est la vie”, which finished 10th. She represented Sweden at the international Eurovision Song Contest 1960 in London with “Alla abdra far varann”, a song originally performed by Östen Warnerbring and Inger Berggren in the Swedish pre-selection. In turn, the following year Malmkvist, who famously forgot the lyrics to the song during her performance, and Gunnar Wiklund both won Melodifestivalen with the song “April,april”, but then Sveriges Radio selected Barbro “Lill-Babs” Svensson the Swedish representative at the national Contest, held in Cannes. In 1969 Malmkvist again returned to Eurovision, but then performing the German entry “Primaballerina” at Madrid, incidentally finishing shared 9th with the Swedish entry “Judy, min vän”, sung by Tommy Körberg.