Next season, new sounds from the Philadelphia Orchestra

If Yannick Nézet-Séguin's current season with the Philadelphia Orchestra seemed unduly loaded with familiar repertoire, the 2014-15 season announced Wednesday has built-in newness: In anticipation of the music director's 40th birthday in 2015, the season will be dominated by the "40/40 Project" - 40 works not played by the orchestra during his lifetime.

"I don't feel our seasons were cautious but an exploration of what the orchestra does in this or that repertoire . . . and how we apply our sound to new repertoire. For this, I needed a bit of time," he said backstage at the Kimmel Center. "I can say openly that [the current season] has nothing to do with being safe . . . I want to open doors but don't want to close others behind me."

Some "40/40" selections promise nothing radical - oddly neglected suites from The Nutcracker and Porgy and Bess, Leopold Stokowski's orchestration of the Rachmaninoff Prelude in C-sharp minor. But more sizable works include Janacek's Glagolitic Mass (Oct. 16-18); Magnus Lindberg's GRAFFITI, for chorus and orchestra (April 23-25, 2015); and the North American premiere of Mark-Anthony Turnage's jazzy Piano Concerto (Jan. 22-23, 2015).

Nézet-Séguin may be furthest out on a limb with the Bernstein Mass (April 30-May 3, 2015), a sprawling, heterogenous work acclaimed in some quarters and dismissed as self-consciously trendy in others. Conductors such as Marin Alsop and Kent Nagano have raised the piece's profile of late.

"I think Bernstein is one of the most brilliant geniuses of the 20th century," said Nézet-Séguin. "He was really before his time . . . combining all of his areas that he was comfortable in and feeling that they all belonged to the same unit."

The role of the celebrant will be played by Schuler Hensley, known for Wozzeck in Philadelphia and Young Frankenstein on Broadway. It will be staged by Kevin Newbury.

Another looming influence over the season is the orchestra's 2015 European tour - Nézet-Séguin's first with the Philadelphians. He wanted Rachmaninoff's Symphony No. 3 (May 13-16, 2015) - and decided to schedule the composer's other two symphonies throughout the season (No. 1 on Oct. 8-11 and No. 2 on Jan. 22-23, 2015). A new, as-yet-untitled Nico Muhly piece, commissioned on relatively short notice, is also in the works for the tour.

 Though there's no official new-concerto festival, Jennifer Higdon's Violin Concerto will be played Feb. 26-28 and Michael Daugherty's Reflection on the Mississippi for tuba and orchestra March 27-28. There will, however, be an Art of the Pipe Organ festival Oct. 31-Nov. 8 with three organ concertos played by three organists. "It's an extension of my choral works, having been a religious musician for most of my teens," he said. Among them is Stephen Paulus' Grand Concerto for Organ and Orchestra, which had a successful outing with the Chamber Orchestra of Philadelphia this season. "It's maybe the best organ concerto I know," said Nézet-Séguin.

Other major events include Mahler's Symphony No. 2 ("Resurrection") with Sarah Connolly and Angela Meade (Oct. 30-Nov. 1), a three-week St. Petersburg Festival in January, and associate conductor Cristian Macelaru leading a Valentine's Day concert of Shakesepeare-inspired music with the Philadelphia Shakespeare Theatre.

One rerun is Bach's St. Matthew Passion (April 1 and 4, 2015), long absent from the orchestra's programs but performed with great success in the 2012-13 season. "I don't want to be obsessed with novelty here," he said. "My first instinct was to do the St. John Passion . . . and I will some day. But let's first go one level deeper with the St. Matthew Passion. Also, we had a lot of e-mails and letters asking us to do it again."

Another popular request came out of his post-concert chats with the audience: Vaughan Williams' Symphony No. 4 (March 5-7, 2015).

The Oct. 10 season-opening night will break from the formality of past years with an evening of French music for which the audience is encouraged to dress flamboyantly.

Nézet-Séguin's next-season commitment to the orchestra includes 11 subscription weeks, plus one for the St. Matthew Passion, three tour weeks, and summer dates to be announced - more than originally planned. The current season has him on 11 subscription concerts (with two weeks canceled), three tour weeks, and two summer weeks.

A number of the 2014-15 concerts benefit from Nézet-Séguin's European residencies with the Rotterdam Philharmonic Orchestra and London Philharmonic Orchestra, yielding artists with major European careers who are seldom heard here. Among them are cellist Jean-Guihen Queyras and violinist Alina Ibragimova.

Guest conductors will include subscription debuts by the Finnish modern-music specialist Susanna Malkki, period-performance specialist Paul Goodwin, and the up-and-coming Czech conductor Jakob Hrusa. Returning are Alan Gilbert, Robert Spano, Gianandrea Noseda, Vladimir Jurowski, Christoph Eschenbach, Valery Gergiev, Rafael Fruhbeck de Burgos, Robin Ticciati, and Stephane Deneve. Pianists include Lang Lang, Jean-Yves Thibaudet, Marc-Andre Hamelin, Kirill Gerstein, and Imogen Cooper. Violinists are mostly such frequent visitors as Gil Shaham, Nadja Salerno-Sonnenberg, and Sarah Chang. Further details and dates are available on the orchestra website, www.philorch.org.