It is annoying as hell to get to, cold, and ridiculously difficult to find seats at, but its free.  And its the Stern Grove Concerts.  

Here is the schedule.

Admission Free Concerts2011 SEASON

• JUNE 19, 2011
  SHARON JONES AND THE DAP-KINGS
  Ben L'Oncle Soul
• JUNE 26, 2011
  JAZZ MAFIA SYMPHONY
  Featuring Chali 2Na
• JULY 3, 2011
  NEKO CASE
  The Dodos
• JULY 10, 2011
  AFROCUBISM
  Pellejo Seco
• JULY 17, 2011
  THE ENGLISH BEAT
  My First Earthquake
• JULY 24, 2011
  SAN FRANCISCO SYMPHONY
  
• JULY 31, 2011
  SAN FRANCISCO BALLET
  Helgi Tomasson, Artistic Director
• AUGUST 7, 2011
  AARON NEVILLE
  Quinn Deveaux and the Blue Beat Review
• AUGUST 14, 2011
  JAVIER LIMON AND BUIKA
  Luisa Maita
• AUGUST 21, 2011
  SAN FRANCISCO OPERA

The one that I am particularly interested in is the one on June 26, Jazz Mafia:  Emperor Norton Suite:

Innovative Bay Area ensemble Jazz Mafia Symphony perform their genre-defying fusion of jazz, funk, hip-hop, electronica, and symphonic music.

The program includes the world premiere of a new work,Symphony No. 2, The Emperor Norton Suite, celebrating the spirit of San Francisco’s favorite eccentric.

Chali 2na, known for his MC skills with hip-hop group Jurassic 5 and Ozomatli, guest stars.

Might be something to check out.  I am not sure I can make it due to a conflict, but I enjoyed their first suite a few years back.  So, go!  And maybe there is something else on there that interests you.  

But make sure to show up early, otherwise it gets PAAAAAAAAAAAAAAAACKED!