Louise Hoffsten is a Swedish rock singer, well-known in her home country, but I have to admit I'd never heard of her prior to her recorded version of "Opium För Dig" (a Swedish translation of the song "You're A Mystery To Me").

A quick web search produced the following bio:

Louise comes from Linköping, but now lives in Stockholm. Her dad Gunnar Hoffsten plays trumpet in a jazz band and also works in a record shop called Skiv-City in downtown Linköping. Her brother is an artist and also lives in Linköping. Besides having produced several albums, Louise is a first-class on-stage entertainer. She writes her own lyrics and music, sings, and plays the harmonica.

In 1997, Louise acknowledge that she is suffering from the degenerative disease Multiple Sclerosis. Despite this however, she made an unexpected comeback in the fall of 1998 as a "Children's Radio" story-teller.

In 2004 Louise was appointed an "honorary doctor" by the university of Linköping for her extraordinary musical contributions and for publicly sharing her personal experience with MS - (thanks to Andreas Ekstrom for the update).