Who has performed as a member of more musical groups, Alexi Laiho or Jónsi?
Alexi Laiho:  He has previously played with Thy Serpent and Impaled Nazarene on occasion, as well as Warmen and Hypocrisy. Jónsi: Jón Þór "Jónsi" Birgisson (] ) (born 23 April 1975) is the guitarist and vocalist for the Icelandic post-rock band Sigur Rós.
i don't know