Bassist for Fun.
Who is the bassist on Aim and Ignite? Andrew Dost? Wiki says he's the bassist for fun., but a search for "bassist fun." points to Jack Antonoff. Anyone have one of those shiny plastic circle things that come with the paper with pictures and words that say who plays what on what?
Whoever it is, they get props for some really inventive playing. And I think that album is great in general.