I kind of think the vocals on their first album ruin a lot of it for me. The guy really improved on their next album, but I'd love to listen to The Observer's instrumentals...
Man...the vocals on their last two albums ruin them for me. Their first album is instrumental and there are a lot of extended instrumental passages and songs sprinkled throughout their discography so this shouldn't be much of a reach.
I jam the instrumental version of Crack the Skye and wonder where the other versions are? Instrumental versions of their first few albums might actually make me want to listen to them.
Clean Mastodon vocals > Harsh Mastodon vocals