You always learn a lot from plays about South Africa. ''A Lesson From Aloes, '' ''Master Harold . . . and The Boys,'' and ''Sizwe Banzi Is Dead'' all provide bleak illustrations of life for South African blacks under apartheid, as well as glimpses at a vital and enduring people who are nonetheless able to laugh.
''Woza Albert!,'' which ended its five-city national tour at Brandeis University's Spingold Theater last week, is no exception. Created by the two actors who perform it, it is a funny, searing, ultimately disturbing play about the reactions of both blacks and whites to the Second Coming of Jesus Christ, who arrives in Johannesburg by jumbo jet. Blacks ask for ''work, . . . chicken wings, and a whole cabbage.'' Whites call out the attack dogs.
Make no bones about it, it is political theater, designed to inform, rebuke, and generally shake up the audience. But the beauty of ''Woza Albert!'' is that it's so artfully done, one never feels manipulated. The play is a series of vignettes that gradually form coherent scenes. It developed out of some improvisations actors Percy Mtwa and Mbongeni Ngema did in 1981. After traveling with a play for weeks through the townships without pay, they weren't allowed to perform to their first sold-out crowd because they lacked the proper permit. These kinds of experiences are the stuff from which South African plays are born , and are the reason the plays are frequently great.