Last summer at Grant Park the Lyric Opera Center for American Artists mounted a fairly successful revival of Peter Brook's eccentric, abridged version of Bizet's Carmen. The staging managed to make the most out of the conceit by focusing on the opera's smouldering passion instead of its social observations; the ensemble singing, for the most part, was excellent and provided a vivid reminder of the importance of the center as a training ground for talented newcomers. This time, the same creative team and most of the same singers return in another challenging (this time uncut) opera: Mozart's Don Giovanni. Stephen Brown directs, and he seems to know how to choreograph on the cramped stage of the Petrillo Music Shell. Also returning is conductor Randall Behr, whose direction of the Grant Park Symphony Orchestra was especially good during Carmen's more psychologically nuanced scenes. Other standouts from last summer include baritone Victor Beneditti in the plum role of the don, tenor Rodrick Dixon as Ottavio, and bass-baritone Elias Mokole as Masetto. On the distaff side are a trio of budding sopranos: Emily Magee (Donna Anna), Elizabeth Koch (Donna Elvira), and Kimberly Jones (Zerlina). They are one of the reasons operagoing can be so exciting: the right to brag about discovering new voices. Friday and Sunday, 8 PM, Petrillo Music Shell, Grant Park, Columbus and Jackson; 819-0614 or 332-2244. The production will be repeated, with Barbara Schubert presiding over the University of Chicago Symphony Orchestra and Summer Chorus, next Friday and Saturday, August 6 and 7, 8 PM, Hutchinson Courtyard, University of Chicago, 1131 E. 57th; 702-8484 or 332-2244.