New term I just thought of, one I think might be useful: "collective pop." This indicates music made in collective/communal fashion by large groups that are often referred to (sometimes by themselves) as "collectives" rather than "bands." Revolving membership is a near-must; bedroom 4-tracks are common among most members and liberally mined for album tracks. Because socialized medicine in the '00s is very different from drugs in the '70s, nearly every collective pop band is Canadian. Examples: Arcade Fire, Stars, Broken Social Scene, Animal Collective, all their many offshoots.
I used to sell hologram bolo ties at the Mall of America