Maybe you heard rumors of its demise, but Anonymous 4, the popular a cappella group, comes to Philadelphia next season - once again - for its traditional Christmas-time concert in St. Mark's Church.

As part of the same Philadelphia Chamber Music Society season, Metropolitan Opera tenor Matthew Polenzani makes his local recital debut.

And chamber music fans will be able to hear superb clarinetist Ricardo Morales, the string-quartet bliss known as the Takács Quartet, emergent pianist Jonathan Biss and veteran Mitsuko Uchida, virtuoso violinist Christian Tetzlaff, Coletrane-esque Kenny Garrett with his Quartet and the Fireworks Music Ensemble in Stravinsky and Frank Zappa.

The society's 2007-08 season offers more than 60 concerts (plus 50 educational programs) at 10 venues across the city.

The season also brings to town more than a dozen local premieres and new works by composers Thomas Adès, Kaija Saariaho, Esa-Pekka Salonen, Elliott Carter, Kevin Puts and Erkki-Sven Tüür.

String quartets are well represented - there are 16 on the roster next season - with performances by the Guarneri, St. Lawrence, Miami, Brentano, Johannes, Juilliard, Tokyo, Emerson, Mendelssohn and others.

The piano recital series features Gary Graffman with works of Brahms and Leon Kirchner; Richard Goode in his core repertoire of Beethoven and Debussy; Christian Zacharias in Schumann and Schubert; Piotr Anderszewski in Mozart and Bach; Pierre-Laurent Aimard playing the Philadelphia premieres of Carter's Two Diversions and George Benjamin's Piano Figures (cushioned by a lot of Bach); and Garrick Ohlsson taking on Prokofiev and Scriabin.

Cellist Jan Vogler, violinist Leila Josefowicz, violinist Joan Kwuon (with pianist André Previn) and Tetzlaff make up the string recital series.

Clarinetist Anthony McGill is joined by a chamber orchestra from the Curtis Institute of Music at the Perelman Theater.

Other musicians participating in various chamber music configurations are pianist Ignat Solzhenitsyn, cellist Peter Stumpf, soprano Joyce DiDonato, pianist Natalie Zhu, the Met Opera Players, pianist (and so much more) Uri Caine, mezzo Tamara Mumford, violinist Timothy Fain and pianist Han-Chien Lee.

Anonymous 4 set off grief in certain circles a few years ago when it announced it would no longer tour full time. The group sang a "farewell" concert in 2003 at St. Mark's Church.

But in practice, the change has simply meant fewer concerts. The four women, who specialize in early music, were typically doing about 60 appearances each season. Next season so far, they have 35 concerts booked, their manager said, including their return to Philadelphia.