Wow, I hope nobody is planning on sitting at home this weekend! In addition to the Greek Festival and the Gateway Cup bike race, there are also several FREE concerts and a parade!
Friday night is the Battle of the Marching Bands in preparation for the Mizzou v. Illinois game. Activities start at 5pm and go until midnight on Laclede's Landing. The bands are supposed to be at the Big Muddy main stage at the corner of There will be a tug of rope contest across Eads Bridge and Robert Randolph & The Family Band will be playing from 8-10:30pm.
Saturday at 3pm is the start of the Big Muddy Blues Festival, also on Laclede's Landing. The festival is FREE (although of course food and beverages aren't). The music lasts until about midnight, and there are 3 stages so you should be able to find some great music that suits your style.