Double-decker or Dubbelplansfiol is a recent and colloquial name of the dominant variant of preserved Swedish violins with sympathetic strings, what they were called when they originated in the 18th century is not known. The Swedish collector of musical instruments Daniel Fryklund writes in 1921 that "In Sweden, the author has found several violini d'amore of a peculiar type with 4 strings and 8 resonance strings, of which the later are attached to small pegs, which are placed behind the larger screws for the playing strings in a pegbox which is extended backwards and such an arrangement of the pegs is not observed by the author on any other violin".[1] Thus, Fryklund suggests it is a specific instrument type typical for Sweden but since he only has observed five instruments he does not conclude it and calls it with the more unspecific name violino d'amore. Today more specimens have been found and out of 27 preserved Swedish violins with sympathetic strings in total, 23 are Double-deckers.[2] Also three of the four preserved instruments that are not Double-deckers are built during the 20th century, while the vast majority of the Double-deckers with a known origin are built during the 18th century which indicates that the Double-deckers are both earlier and dominant[2]