Philip Glass' native Baltimore Symphony is doing a concert featuring two hometown composers: Frank Zappa and Philip Glass.  Marin Alsop, who recorded Heroes Symphony for Naxos, is conducting. She's been doing a lot of Glass recently with the UK premiere of the Violin Concerto No.2 "The American Four Seasons," the UK premiere of ICARUS: At the Edge of Time also with the London Philharmonic Orchestra, and in August Alsop will be conducting the Glass Cello Concerto at the Cabrillo Festival.  Here's a link to this Friday's concert featuring Glass' Symphony No.4 "Heroes"