The 17th-century French composer Marc-Antoine Charpentier wrote his share of theatrical and other secular music, but he's best remembered as a composer of works on religious themes, most notably from his years as master of music at Sainte Chapelle, one of France's two most prestigious church music posts at the time. His harmonic inventions and idiosyncratic use of vocal color make his music particularly engaging. In this week's concerts Music of the Baroque will offer a pair of Charpentier premieres--The Prodigal Son and (pushing the season a bit) Midnight Mass for Christmas--and one revival of a Charpentier work presented in the group's first season, Laetatus Sum. This will be a relatively intimate evening by Music of the Baroque standards, with only 27 musicians--a 13-member chorus with step-out soloists, a 13-member orchestra, and one conductor--performing some truly ravishing music. Tuesday, 8 PM, Episcopal Church of St. Luke, 939 Hinman, Evanston. Thursday, 8 PM, Notre Dame of Chicago Church, 1336 W. Flournoy. 551-1415.