EL CORO SHALOM, a 24-member vocal ensemble from Havana, Cuba, will visit Carleton Thursday, September 13th.  Activities will include an informal discussion of Cuban culture with members of the choir (4:00 p.m in the Weitz Center), a musical "exchange" with the Carleton Choir (5:30 p.m. in the Concert Hall), and a formal concert at 8:00 p.m. in the Concert Hall.