Elsa Sigfúss.

Elsa Sigfúss was the daughter of Valborg Helleman and Sigfús Einarsson, composer and pioneer of Icelandic musical life. Elsa likely recorded on more records than any other Icelander, and she was a popular singer throughout Scandinavia well into the years following the Second World War.

Tónlistarsafn Íslands at Landsbókasafn Íslands – Háskólabókasafn preserves a wide range of materials related to Elsa and her career, including recordings, concert programs, correspondence, newspaper clippings, and photographs.

Source: Ísmús biography page