The New York Philharmonic formally opens its 2007–08 season tomorrow night, with a gala concert featuring Yo-Yo Ma. But the orchestra had an informal opening on Friday night, when John Williams led them in a program of movie music. The program was repeated on Saturday and Sunday nights (and I attended the middle concert).

Mr. Williams, of course, is the preeminent film composer in America; he is also a conductor of wide experience. You perhaps know a favorite quote from Leonard Bernstein: “I’d give five years of my life to have written ‘The Stars and Stripes Forever.'” Well, would you give five years of your life to have written the theme to “Raiders of the Lost Ark” or the theme to the “NBC Nightly News” (called “The Mission”)? No? Okay, how about a long weekend?

When Mr. Williams took the stage on Saturday night, he was greeted by thunderous, almost shocking applause; and it occurred to me that he is probably the most popular composer of classical music in the country. (And let us not define classical music too narrowly.) Who else approaches him, really? As for his conducting, it is efficient, competent, unshowy — he tends to let the music do the talking.

And his music tends to be optimistic, broad, reassuring. He has no one style, of course, because a film composer has to be a chameleon, perhaps above all composers. But there is still a familiar Williams strain.

He and the Philharmonic opened their program with “Sound the Bells!” written for a Japanese royal wedding in 1993. The playing was bright and belly — maybe overly bright. Then we heard “Flight to Neverland” from the movie “Hook.” This is some of that flying music in which Mr. Williams specializes (think E.T. on a bicycle). He really knows how to put movement in music, making it soaring, wide-eyed, and rhapsodic.

From a TV version of “Jane Eyre” (1971), we had a little suite of three pieces. In the first, the Philharmonic committed many bobbles, but it didn’t seem to matter much. Then we had a suite from the “Harry Potter” movies (which reminds me to ask: How rich do you think John Williams is?). “Hedwig’s Theme” is the picture — the aural picture — of magic and wizardry. That, indeed, is movie music.

Mr. Williams closed the first half of the program with a pastiche from “Fiddler on the Roof” — he adapted Jerry Bock’s score for the 1971 movie. And playing the role of Isaac Stern, so to speak – Stern was the violinist in the movie soundtrack — was Glenn Dicterow, the Philharmonic’s concertmaster. Beforehand, Mr. Williams told the audience that he was once an “alternate pianist” in the Los Angeles Philharmonic. He knew Harold Dicterow, a prominent violinist in that orchestra, and “loved” him. Harold had a 10-year-old son, Glenn, who was a whiz. And who should be onstage tonight?

Mr. Dicterow played his “Fiddler” music stylishly, accurately, and beautifully. He let it have its dignity, with no schmaltz or ham.

The second half of the program opened with “Hooray for Hollywood!” Just as no one knows the words beyond the first three, no one knows who wrote this anthemic piece: Richard A. Whiting, for “Hollywood Hotel.” The Philharmonic played the piece awfully noisily and bangily, which was not entirely necessary.

Then, Mr. Williams and the orchestra staged a tribute to Stanley Donen, director of such films as “Funny Face,” “Pajama Game,” and “Two for the Road.” Mr. Donen was on hand, to talk about his films — and the orchestra accompanied some key scenes. Mr. Williams had a little screen in front of him. (He was looking at the screen and the score at the same time.) The audience had a big screen, hanging behind the orchestra.

There was Fred Astaire, dancing on the ceiling (in “Royal Wedding”). There was the hoedown from “Seven Brides for Seven Brothers” — thrilling. And then there were three bits featuring Gene Kelly, including a scene on rollerskates (“It’s Always Fair Weather”). In a typically entertaining remark, Mr. Donen said, “Gene was the only man on earth — or anywhere else — who could have pulled that off.”

Two years ago, Mr. Williams wrote the music for “Memoirs of a Geisha,” and from that score we heard “Sayuri’s Theme.” Carter Brey, the Philharmonic’s principal cello, was soloist, and he was tangy, shivery, and Japanesey — perfect. Then Mr. Williams closed the printed program with a medley of music from his George Lucas and Steven Spielberg movies. Images from those movies appeared onscreen. One by one they came — “Jaws,” “Star Wars,” “Raiders,” “E.T.” — and the audience roared with each one. This was an act of communal memory. Mr. Williams is an important figure in contemporary American culture — and, of course, Messrs. Lucas and Spielberg aren’t unimportant either.

Frankly, Mr. Williams’s conducting in this medley was rather pedestrian. He could have treated his own music with more flair and drama. But, again, he is unassuming, and competent. And at least he’s never overwrought.

There were three encores, all from the pen of the conductor. First was a piece from “The Sugarland Express,” an early Spielberg movie. It is mainly a flute solo, and Robert Langevin played with his accustomed expertise, technical and musical. Then came some work done for the 1988 Summer Olympics (Seoul). And, finally, probably my favorite Williams piece of all: that bit for NBC News, “The Mission.”

You might have thought this would be just sort of a dumb pops concert, before the formal opening of the Philharmonic season. Actually, it was wonderful.