Since 1971, this heavily subscribed, perennially popular and influential African-American theater has encouraged many new works and voices in its South Shore space. Led by its co-founder and CEO, Abena Joan Brown and artistic director Runako Jahi, it has produced an astonishing number of plays over the years. Among seminal offerings was ''Get Ready,'' Jaye Stewart and Joe Plummer's affectionate tribute to the doo-wop groups of the 1950s. ETA's Playwrights Discovery Development Initiative, which includes residences and workshops for its playwrights, yielded ''The Temple.'' Charlotte Cibson and the hilarious face-off called ''The Trial of One Short-Sighted Black Woman vs. Mammie Louise and Safreeta Mae,'' by Marcia L. Leslie. Fully 98 percent of ETA's plays are world premieres, including Ron Milner's ''Urban Transitions: Loose Blossoms'' and his ''Checkmates,'' which went on to play five more theaters before hitting New York. The theater is only one part of the foundation's community center, which includes two art galleries, classrooms and recreational facilities. Good seats, air conditioning, sight lines and acoustics.