Complex sentence: During the 80s as countries like Argentina, Uruguay and Brazil returned to democracy many bands would return to their countries but in the cases of Chile more groups would continue to go into exile like Illapu who left Chile in 1981.
Split into simpler sentences: During the 80s, as countries like Argentina, Uruguay and Brazil returned to democracy, many bands would return to their countries. In the case of Chile, however, more groups would continue to go into exile, such as Illapu who left Chile in 1981.