NEW ERA BEGINS WITH DAYTON PHILHARMONIC DATE: Sunday, September 3, 1995     By Mark Stryker DAYTON DAILY NEWS                               DAYTON DAILY NEWS                   Copyright (c) 1995, Dayton Newspapers Inc.   No local arts group has a greater right to crow about starting a new era with its 1995-96 season than the Dayton Philharmonic Orchestra.   After all, nothing signifies change in an orchestra more than a new music director. And the Dayton Philharmonic starts its 62nd season with a new man holding the artistic reins.   Neal Gittleman, only the fourth music director in the orchestra's history, replaces Isaiah Jackson, who concluded a productive but stormy 8-year relationship with the orchestra in May. Gittleman, 40, is currently the resident conductor of the Milwaukee Symphony and music director of the Marion (Ind.) Philharmonic.   Since Gittleman will spend the next 18 months juggling responsibilities with all three orchestras, you might expect him to look a little harried off the podium. But based on his audition concert last fall, in which he led a moving account of the Shostakovich 5th Symphony , expect some deadly serious music-making from this Yale graduate, whose training includes studies with Nadia Boulanger and Charles Bruck, as well as positions with the Oregon and Syracuse symphonies.   As the season continues, careful listeners should begin to hear what Gittleman's musical priorities will be. How does he hear the sound of an orchestra? What character of sound does he prefer? How sophisticated is his sense of musical architecture? How convincing is he in the classical, romanticand modern repertory? How flexible is his phrasing and sense of time? How willhe answer crucial questions of balance, dynamics and tempo? And how successfulwill he be in communicating his vision to the orchestra?   By any estimation, it should be a fascinating year.CLASSIC INFO   For ticket and schedule information call:   * Dayton Philharmonic Orchestra, 224-9000.   * Dayton Bach Society, 256-2224.   * Dayton Opera, 228-7464.   * Vanguard Concert Series, 434-6902.   * Soirees Musicales Piano Series, 228-5802.   * Chamber Music Yellow Springs, 767-1750.   * Wright State University Artists Series, 873-5544.   * Miami University Performing Arts Series, 529-6333.   * Sorg Opera, 425-0180.LENGTH: Medium:   53 LINESILLUSTRATION: PHOTO: Neal GittlemanSUBJ: CLASSICAL MUSIC NA: DAYTON PHILHARMONIC ORCHESTRA   NEAL GITTLEMAN ENHANCER: REF1