As closers go, the final classical concert of the Bangor Symphony Orchestra season was a winner. Those who gave up the sunny Sunday afternoon Red Sox game for the BSO concert at the Maine Center for the Arts got all homers. And ultimately, the concert was just like the Sox game: worth the wait.

The program opened with Mozart’s “little” G Minor Symphony – No. 25, K. 183 – during which Maestro Xiao-Lu Li led the musicians through a fetching and toe-tapping performance.

All ears then turned to Lydia Kilian, a young pianist and winner of the BSO Maine High School Concerto Competition. The Weeks Mills student stepped declaratively into Edvard Grieg’s dramatic Piano Concerto in A Minor, playing with urgency in some places, modesty in others. She seemed to have the piece memorized, but turning pages of the score gave her a few stumbles. Still, nothing could keep the rapt audience from a major standing O at the end.

Kilian wasn’t the only debut of the day. The orchestra proudly gave the world premiere of “Bangor Overture,” a zippy miniature by BSO cellist Richard Francis. The composition alluded to fanfares, marches and Morse Code. (The word “Bangor” was secretly spelled out in the xylophone part.) Francis wrote the piece while he was building a house, and maybe that, too, had an influence. It was noisy all right – in a stirringly percussive way.

And it made a delicious pairing with Dmitri Shostakovich’s Symphony No. 9 in E flat major, a joyful, if jesting, work. Here, Li gave a light reading, with carefully moderated speeds and enticing energy.

American orchestras are increasingly struggling to find the right balance between old and new, traditional and contemporary, reverent and racy. Sunday’s concert had it all.