Each holiday season in America, George Handel's "Messiah" dominates the classical musical offerings. But in northern Europe, the story has different accompaniment. There, J.S. Bach's "Christmas Oratorio" is the tradition.

"In Holland, Scandinavia and Germany, you hear the 'Christmas Oratorio' -- they grew up with it," says Don Franklin, the University of Pittsburgh professor and Bach specialist who directs Pitt's Bach and the Baroque concert series. "You don't hear it performed very often in America."

That's reflected in the history of Franklin's series. While it has performed 30 Bach cantatas, his "St. Matthew" and "St. John" Passions, "Magnificat" and more, the group has never performed the "Christmas Oratorio." Franklin will rectify that in the nick of time: Its December performances of the complete oratorio will be the last concerts for Bach and the Baroque. Franklin plans on retiring from Pitt in the spring of 2009 and wanted to finish the series with this season.

"It has been an enriching experience," says Franklin, who founded it in 1991 with the urging John Goldsmith, director of choral activities at Pitt and leader of the Bellefield Singers. "I told him we have built-in soloists and all you need is an orchestra," says Goldsmith.

"It began as an expanded lab of the things we were talking about in my Pitt seminars," says Franklin. Students, faculty members and freelance musicians filled out the ensemble.

"We struggled along for the first few years with modern instruments, then Chatham Baroque started and that was a catalyst," says Goldsmith. "The last years have just had wonderful period orchestra performances." Franklin concurs, calling the performance in 2000 of the "St. Matthew Passion" a "high point."

"This is one of my favorite things to do," says violinist Julie Andrijeski of Chatham Baroque.

On several occasions, Franklin has given modern-day "premieres" of works, such as "St. Matthew Passions" by C.P.E. Bach (Bach's son) and by Telemann, and "Missa Novi Regis" by Antonio Bertali.

"It is so exciting to find a work, to shape it and bring it alive," says Andrijeski.

Just as many of J.S. Bach's finest compositions were performed at St. Thomas Church in Leipzig, Franklin has had his own glorious venue: Heinz Chapel. "The setting of the Gothic structure is so special."

Those involved with the series feel the same way about Franklin.

"He is a gentle, sweet guy, a musical Bach scholar," says Goldsmith.

"His knowledge of Bach is immense," says Andrejski. "I was always so impressed about how much he knew about the music and the text, which he would teach the chorus."

Born in Willmer, Minn., Franklin accompanied a chorus under conductor Antal Dorati while at the University of Minneapolis and studied harpsichord with Gustav Leonhardt. His switch to research led to a deeper engagement with Bach, and in 1976 he won a Fulbright fellowship to study in Germany.

"I wanted to know everything about Bach's music -- including visiting the places he worked, reading the religious texts in his library and seeing his working conditions."

Composed about a decade earlier than Handel's famous oratorio, "Messiah," Bach's "Christmas Oratorio" of 1734-35 differs substantially. The oratorio, Bach's first, is not a continuous concert piece like "Messiah" but a cycle of six cantatas for separate Lutheran worship services: on the three days of Christmas, New Year's Day, the Sunday after and Epiphany. Performances of the cantatas took place at both St. Thomas and St. Nicholas churches in Leipzig. Each had a place of prominence in the first half of the services comparable to that of the sermon in the second half.

"Today it is performed as a concert piece," says Franklin, who will split the oratorio into two concerts, presented by the Renaissance & Baroque Society.

Bach imbued his "Christmas Oratorio" with joy for the occasion, but for early music lovers across Pittsburgh, next weekend will be bittersweet.