Gjallarhorn are from the Swedish-speaking area of Finland, and as a result their lyrics are sung in Swedish (as opposed to Finnish, as one might expect of a Helsinki-based band). Although fairly traditional, the band does incorporate ethnic percussion instruments (from all different areas of the world) into their music, and uses a didgeridoo as their drone instrument (most bands use either hurdy-gurdy or Swedish bagpipes). This has gained Gjallarhorn some appeal among world music connoisseurs.
Hedningarna’s music is largely planted in Finnish tradition (even though the band itself is actually from Sweden), and is among the most rock-influenced of the Scandinavian folk bands. Hedningarna has also been around for quite some time, having released their first album in 1988. Compared to Garmarna and Sorten Muld, the band usually has a brighter, more cheerful sound. Hedningarna has been substantially influenced by rock bands such as Jethro Tull.
Värttinä is a Finnish band, playing a variety of Finnish folk and folk-inspired music. Their music consists mainly of several female voice parts, as well as accordion, kantele, bass, wind and percussion.
Link in comments