Which band had more members in its original line-up, 311 or Mercury Rev?
311 (band):  The band was formed in 1988 by vocalist and guitarist Nick Hexum, lead guitarist Jim Watson (a member briefly, before being replaced by Tim Mahoney in 1991), bassist Aaron "P-Nut" Wills. Mercury Rev: Mercury Rev is an American indie rock band formed in 1989 in Buffalo, New York. Mercury Rev:  Original personnel were David Baker (vocals), Jonathan Donahue (vocals, guitars), Sean Mackowiak, a.k.a. "Grasshopper" (guitars, clarinet), Suzanne Thorpe (flute), Dave Fridmann (bass) and Jimy Chambers (drums).
Mercury Rev