Bach's GREATEST HITS; American Bach Project Festival Schedule Mainstage Events Friday: Musica Antiqua Koln features Brandenburg Concertos and related works, 7:30 p.m. Pabst Theater, 144 E. Wells St. Single tickets $30 and $22.50. March 17: Apollo's Fire (Cleveland Baroque Orchestra), performs secular cantatas staged by James Middleton, of Ex Machina Antique Music Theater, 7:30 p.m., Wisconsin Lutheran College, 8815 W. Wisconsin Ave., $20. Lecture by James Middleton, Ex Machina artistic director, at 6:30 p.m., on "The Baroque Stage: A Neglected Period Instrument." March 21: Trio Sonnerie with flutist Wilbert Hazelzet, featuring the trio from "A Musical Offering" and other chamber works, 7:30 p.m. at All Saints Cathedral, 818 E. Juneau Ave., $20. Lecture by David Schulenberg, University of North Carolina, at 6:30 p.m.,on "Bach Goes to Court: J.S. Bach and His Royal Patrons." March 22: Ensemble Musical Offering, with harpsichordists Edward Parmentier and Joan Parsley, perform concertos for two harpsichords, Palm Sunday Cantata, 7:30 p.m., All Saints, $20. Lecture by David Schulenberg at 6:30 p.m. on "Recycled and Revised: How Bach Kept His Concertos and Cantatas Up-to-Date." March 23: Parmentier performs Chromatic Fantasy and Fugue, Italian Concerto in D, and more, 7:30 p.m. at All Saints, $20. Lecture by Laurence Libin, Metropolitan Museum of Art, at 6:30 p.m. on "Bach: The Instrumental Innovator." BachNacht Concerts For those who can't get enough Bach on the mainstage, there is a series of intimate, informal and somewhat briefer concerts. Single tickets are $10. Harpsichordist Vivian Montgomery and recorder player Clea Galhano, 4 and 8 p.m. Saturday, All Saints Cathedral, 818 E. Juneau Ave. Harpsichordist Martha Folts, 7:30 p.m. next Sunday, Brass Light Gallery, 131 S. 1st St. Harpsichordist Schulenberg, 7:30 p.m. March 19, All Saints. Parsley and gambist John Mark Rozendaal, 7:30 p.m. March 20, St. John's Evangelical Lutheran Church, 7809 Harwood Ave., Wauwatosa. Parmentier in his third festival program, 10 p.m. March 21, All Saints. Young Artist Showcase Concerts The Historical Keyboard Society invited area piano students to audition. The best of them will play at the Young Artist Showcase Concerts listed below. Each of these programs, aimed at children and their parents, includes an audio-visual presentation on Bach's life and times. Admission is free. 3 p.m. Saturday, Joyce Parker Productions, 2685 S. Kinnickinnic Ave.; 7 p.m. Saturday, Barnes & Noble, 16220 W. Blue Mound Road, Brookfield; 3 p.m. next Sunday, Betty Brinn Children's Museum, 929 E. Wisconsin Ave. (museum admission required); 7 p.m. March 18, Piano Gallery, 219 N. Milwaukee St.; 3 p.m. March 22, Wauwatosa Public Library, 7635 W. North Ave. (MORE INFORMATION ON CONCERTS) Ensemble Musical Offering is, in a sense, the house band of the festival. EMO has a close relation with the Historical Keyboard Society because its leader is keyboard player Joan Parsley, the tireless founder and artistic director. Aptly enough, EMO's Palm Sunday program will be the Bach Cantata for Palm Sunday. It will also showcase Parsley in concertos for one and two harpsichords. Her keyboard partner in the duo-concerto will be Edward Parmentier, one of the festival's headliners. Trio Sonnerie, in February of last year on an Early Music Now concert in Milwaukee, gave a stunning account of virtuoso showpieces by composers a generation or two ahead of Bach. Violinist Monica Huggett, gambist Sarah Cunningham and harpsichordist Gary Cooper played with the wild intensity and abandon associated with Romantic, heroic instrumentalism, and it all sounded quite plausible. The trio, which is based in London, will be joined by Baroque flutist Wilbert Hazelzet. What will they make of "A Musical Offering"? Musica Antiqua Koln is now the hottest early- music group in Europe. Its charismatic leader, violinist-violist Reihard Goebel, has been at the forefront of a more frankly virtuosic and expressive approach to Baroque music that has erased the old plain + dull = authentic equation from the early-music movement. The Historical Keyboard Society brought Goebel and five colleagues to its series for a knockout concert back in 1988 (on this visit, he'll bring the 12-piece Musica Antiqua orchestra). Since then, Goebel has suffered through a disastrous repetitive-stress injury that made it impossible to use his left hand to press the strings to the fingerboard. He solved the problem in an obvious but unthinkable way: He changed hands. Goebel now bows with the left and stops the strings with the right, and reportedly is playing at virtuosic levels. Amazing. Apollo's Fire is the ear-catching nom de marquee of the Cleveland Baroque Orchestra. Conductor Jeanette Sorrell, a protege of both the extravagantly Romantic Leonard Bernstein and the briskly Baroque Roger Norrington, founded the group in 1992. The musicians and singers will not only play the "Coffee" Cantata the closest Bach came to opera but act it. Stage director James Middleton, of Ex Machina Antique Music Theater, is coaching them on Baroque style and making the cantata into a show ("A Gripping Drama of Love and Caffeine Addiction!"). Edward Parmentier will give the heavyweight keyboard show at the festival. Parmentier, a music professor at the University of Michigan, will take on the Chromatic Fantasy and Fugue and other formidable works. He will play on the spanking-new five-octave, double-manual harpsichord built by Paul Ervin, of Glenview, Ill., for the University of Wisconsin-Milwaukee. The basic design dates to a 1638 Franco-Flemish Ruckers harpsichord, incorporating features routinely added to older instruments in the 18th century. ------------ Festival Passes: $140, good for admission to all events of the Historical Keyboard Society's "Bach's Greatest Hits" series; $100, for the five Mainstage Concerts; $40, for a five-concert BachNacht. Single tickets: See the event schedule for prices. To order: Call the Historical Keyboard Society, 226- 2224. Tickets for the Musica Antiqua Koln are also on sale at the Pabst Theater box office, 286-3663.