Which musician, Mikael Åkerfeldt or Dave Pirner, is best known as the lead vocalist and frontman for the alternative rock band Soul Asylum? 
Mikael Åkerfeldt: Lars Mikael Åkerfeldt (born 17 April 1974) is a Swedish musician, prominently known as the lead vocalist, guitarist, and primary songwriter of progressive death metal band Opeth, as well as being the former vocalist of death metal supergroup Bloodbath.
i don't know