Nearly three decades ago Music of the Baroque mounted Bach's B Minor Mass for the first time; the young company's performances of this monumental work (often compared to Michelangelo's Sistine Chapel ceiling in its scope and sublimity) helped make its reputation. It's perhaps significant that MOB's new music director, Jane Glover--only the second leader in the history of the group--chose to open her inaugural season with a revival. Local concertgoers have become familiar with this exciting British conductor in recent years: she's presided over popular Chicago Opera Theatre productions of Monteverdi and Mozart, and in her tryout appearances with MOB she smoothly brought the group around to her musicologically informed interpretations. Whereas her predecessor, founder Thomas Wikman, was never overly concerned with Baroque authenticity, favoring the later bel canto style of singing and a 19th-century orchestral sound, Glover's a keen disciple of the period-instrument movement with a strong academic background (she holds a doctorate from Oxford). I find her to be the more appealing of the two, as musical as Wikman but without his stern metronomic tendencies. For these performances of the mass she'll have some veterans of earlier revivals in both the orchestra and the chorus, but her soloists are largely newcomers to MOB. Three of the four--soprano Nathalie Paulin, mezzo-soprano Phyllis Pancella, and tenor Frank Kelly--are making their debuts with the ensemble, and baritone James Maddalena made his just last season. Pancella is noted for her range and strong stage presence; Maddalena originated the role of Nixon in John Adams's opera Nixon in China; and Paulin was a sensation in recent stagings of Handel's Semele and Acis and Galatea at Chicago Opera Theater. Kelly is the relative unknown here. If Glover and her colleagues are in top form mentally and physically--it's a long work--these performances may well rank alongside those of 29 years ago. Sunday, September 21, 7:30 PM, First United Methodist Church, 1630 Hinman, Evanston. Monday, September 22, 8 PM, Grace Lutheran Church, 7300 W. Division, River Forest. Next Sunday, September 28, 8 PM, St. Paul's United Church of Christ, 2335 N. Orchard. 312-551-1414.