No serious music lover would deny the primal importance of J.S. Bach in the history of the art, and yet performances of his masterpieces are in short supply these days. The main reason, no doubt, is the stylistic limbo his output finds itself in. Major orchestras, which used to routinely program the orchestral suites and concertos, rarely do now, as this is considered "unauthentic." Also now frowned upon is playing his keyboard music on a piano, rather than a harpsichord. It's all a bit ridiculous, since the great music of Bach is as malleable as it comes, and the old man himself frequently changed the arrangements of his own work. This week, the Bach Festival of Philadelphia caps off its 30th year with a week of concerts featuring a gleeful mix of styles. It will be an ambitious undertaking, with almost all of the secular orchestral works on tap, including the Suites, many of the instrumental concertos and all of the beloved Brandenberg Concertos. Most of these programs will be under the direction of festival artistic director Jonathan Sternberg, who was one of the pioneers of the Bach revival that swept the music world after World War II. He will conduct the Philadelphia Bach Festival Orchestra, an excellent ensemble of well-known local freelancers. Out-of-town guests include Cleveland Baroque and the New York Chamber Soloists. There will also be a vocal competition, family events and a special dinner performance by pianist Gary Graffman. The entire enterprise is dedicated to the memory of Michael Korn, who died much too young, 15 years ago this year, and founded the festival 30 years ago. His plaque will be added to the Walk of Fame on the Avenue of the Arts this week.

Bach Festival of Philadelphia: Bach Festival Week, March 17-April 2, 215-247-BACH, www.bach-fest.org.