I saw the Boston Ballet perform last night. The first dance was forgettable, the second a great classic, Jerome Robbins’ “Fancy Free.”

That alone would have been worth the price of admission, with its Bernstein music, its swingy 40s ambiance, and its fabulous three solos for its three show-off sailors that perfectly express their differing personalities, with steps choreographed by Robbins that flow so freely that it seems as though the dancers are improvising them on the spot through an excess of high spirits.

But I was surprised that it was the third ballet, Harald Lander’s “Etudes,” that turned out to be the highlight of the evening for me and much of the audience. It’s a piece I’d seen many times before and liked well enough, back in the 70s and performed by American Ballet Theater, although I’d not seen it since then till last night. A classroom-to-stage ballet, starting with a stylized, revved-up version of the dancers’ daily barre exercises and segueing through various styles of ballets (Romantic, imperial, character), “Etudes” is an ever-accelerating high-speed train ride of a ballet. Forget plot; this is ballet stripped bare of everything but its classical elements: tradition, tutus, and technique.

In the many decades that have passed since I first saw the Boston Ballet its technical skill has vastly improved, as was made abundantly clear last night. “Etudes” is totally unforgiving; it requires ensemble work of tremendous difficulty and everyone not only has to be on the beat, but incredibly powerful and of major soloist caliber. The music (a live orchestra last night, always a huge treat) is based on familiar Czerny exercises, but with the full complement of instruments it built and built along with the choreography until the usually staid Boston audience was practically in a frenzy.

Unfortunately, I don’t have a video of that production, so this will have to do. It’s the Royal Danish Ballet in the last few minutes of what’s actually a 40-minute performance. Recall that dance on video is two-dimensional and only has about one-tenth the impact and depth and pizazz of the same thing seen in person—which last night included, of course, the full orchestra in the glorious Boston Opera House. What’s more, the Boston dancers were significantly better than this crew (who are awfully good, too), even though the piece was originally choreographed for the Danes back in 1948: