Saturday’s concert at Kleinhans Music Hall, a celebration of Mozart’s birthday, drew a big crowd, and many listeners were newcomers.

You could tell, because of the clapping between movements. Seasoned concertgoers refrain until the end of the piece. I don’t think anyone minded the break from convention. Welcome, Mozart fans!

This weekend’s concert begins with the overture to “The Marriage of Figaro” and continues with the Symphony No. 34, winding up with the Concerto for Two Pianos and Orchestra, K. 365. The concerto features dynamic twin pianists Christina and Michelle Naughton.

On the podium is a conductor from Poland, Pawel Przytocki. He did a beautiful job Saturday night bringing out the beauty of this music.

He is a formal figure, in tails, with a crisp and deft way with the baton. The “Marriage of Figaro” overture was brisk and breathless, just as it should be. Przytocki has the rare knack of sculpting the phrases with care without sounding fussy. Strings and woodwinds played with a fine sensitivity, and the music had a satisfying body to it.

The Symphony No. 34 is a piece you do not get to hear too often, and Przytocki brought out its gallantry and charms. In the slow movement, the violins – led by Assistant Concertmaster Angsgarius Aylward, acting as concertmaster – played with a heartfelt simplicity.

The rollicking last movement was the highlight. It’s so much fun, like a reel, and strings and woodwinds, all apparently enjoying themselves, navigated its tumbling triplets with pizzazz. Mozart was a master of the perfect ending, and this symphony has one of his best. Przytocki sold that ending, finessing it just so. The crowd loved it. It was a marvelous moment.

The magnificent double piano concerto, which followed intermission, is a rare pleasure. It’s such a spectacle, with the two pianos pushed together, dominating the stage. It was fascinating to think of the pianists who had played this piece at Kleinhans over the decades: Guy and Lois Maier, Robert and Gaby Casadesus. The most recent performance had been in 1966, with Lukas Foss conducting the now all-but-forgotten team of Arthur Gold and Robert Fizdale.

The Naughton twins, in their early 20s, brought their own brand of showmanship. Stunning in lookalike deep blue gowns, they were adept and very professional. It was impressive how prepared they were, how secure in their memory. You never worried that one of them would slip.

It was also amazing how in synch they were. Even out of the air, after a pause, they could launch a trill at the same millisecond. Their notes were all flawlessly together. They were fun to watch, tackling the music gracefully and fearlessly.

They do have growing up to do. The slow movement of this piece, in the right hands, can make you cry. The Naughtons only skated the music’s surface. In the other movements, too, there were moments when the depth of what Mozart was doing seemed to escape them.

But it was hard to blame them. You have to live a little to understand what this music is about. They have time.

I had to run out the door, but I heard that they gave a great encore, the virtuosic Paganini Variations of Witold Lutoslawski. I wish I had heard it. I’ll bet they rocked it.

This lovely concert repeats at 2:30 p.m. today.