Three original members. Maurice White and Philip Bailey on lead vocals and Verdine White on bass guitar.
They're all pushing or over 60 and they still dance like they're 20. This ranks up there with some of the best shows of my life.
Pearl Jam on the other hand, not so much. There was something like 10,000 people gathered on one lawn to see them (the rest were on the other side of the fairgrounds watching Jeff Beck) and everyone seemed to be thinking "oh man! we're about to see a legendary grunge band" but then they started playing and everyone realized "oh shit, that band is fucking Pearl Jam, never mind"
They played a decent cover of Kick Out the Jams though.