The Downtown Association is gearing up for a huge summer filled with a large variety of events. This includes 2 Music in the Park Concerts (English Beat 7/17 and Pete Escovedo 8/21); 8 free outdoor movie events (80's themed this year); 10 World Cup Soccer Viewing Events with the SJ Earthquakes partnering; 10 days of pre fixe menus during Dine Downtown Restaurant Week; the weekly Downtown Farmers' Market every Friday through Nov. 21, as well as helping with the SoFA SubZERO festival and South First Friday Street MRKTs.
To keep track of all these great events, please check out http://www.sjdowntown.com/summer. That site will be updated regularly all summer long as new events and updates come up.
Also for live music, you definitely have to bookmark http://www.liveandlocalsj.com.