I’m sure wiser heads have commented on this, but I was struck by something while watching Tron: Legacy the other night: the growing influence of minimalism in American movie soundtracks.

Let me back up a bit. In the early 90’s, I saw an outstanding documentary called The Thin Blue Line. Errol Morris, who is the film-maker Michael Moore wishes he were, made a compelling case that an innocent man was on death row — such a compelling case that he was released a year later.

One of the great things about the film is the score, which was put together by minimalist composer Phillip Glass. At the time, I had no idea what minimalist music was. When I first heard the name, I assumed it was what it sounded like — an orchestra where the violin would play one note, the trumpet would play another and that would be it: a more upbeat version of Cage’s silence. But minimalism is more complex than that. And Glass’s score, with its emphasis on rhythm and harmony at the exclusion of melody, was perfect for the movie. It gave an unusual urgency to the narrative and the increasing complexity of the harmony emphasized the increasing complexity of the story you were required to believe to conclude that Randall Dale Adams was guilty.

Glass did another score for The Hours which was very similar — his music all begins to sound alike after a while. But it also elevated that movie, especially the scene where Julianne Moore hallucinates that the room is flooding.

So, back to Tron. Daft Punk’s score is very good and also very minimalist. It is built on a handful of leit motifs with lots of repetition, increasing complexity and changing emphasis. It gives the film almost all of its energy and drive. But Tron is not unique. Inception had a very minimalistic score. Doctor Who uses a fair amount of minimalism. Both Batman movies use a lot of minimalism. Hans Zimmer, in particular, has been driving the minimalist train for several years with dramatic success.

So why is minimalism so big now? I think because it is well-suited to the kind of entertainment we’re seeing — fast-paced, quickly-edited, quick moving films that have little time for symphonic scores. They need a score that moves the movie, rather than emphasizes it. This is especially true of science fiction and fantasy films where a minimalist score can match the “techie” look and feel.

That’s not to slam symphonic scores like those of John Williams, whose epic scores for the three Star Wars prequels were the best things about them. Howard Shore’s score for Lord of the Rings, with its strong Wagnerian influence, is wonderful. But the palette has now broadened to the point where a minimalist score can not only be acceptable, but one of the best scores of the year.

We’re in a golden age of movie scores. If only the scripts could keep up.