There's no list of Scottish music that could ever miss out
Capercaillie, the band with singer Karen Matheson. For many
people her superb "shiny" voice is the epitome of
Scottish/Gaelic music at its best. They are also well-known
for the soundtrack of the film "Rob Roy" (with Liam
Neeson and Jessica Lange).
To get an insight into their music I would recommend "Dusk
till dawn - The best of Capercaillie" (1998).