There's no getting around it: Tar is a long movie. It's not as long as the Avatar sequel or Babylon but it does require a certain level of commitment, both in concentration and in time - and an interest in classical music doesn't hurt. But the experience is worth it: there's a lot to think about in this film and all may not be as it seems.

It's the first film from writer-director Todd Field since Little Children (2006), after years of cancelled projects, and it's been worth the wait, even though we can only wonder what else we might have had.

Composer and conductor Lydia Tar (Cate Blanchett) is at the top of her profession. She's a multi-talented musician who's the respected first female chief conductor of the Berlin Philharmonic. She's won an Emmy, a Grammy, an Oscar, and a Tony award and she's recorded all but one of the Mahler symphonies and is about to record the Fifth to make it a complete cycle.

Personally, things seem good, too. She's married to Sharon (Nina Hoss), the orchestra's concertmaster and they have a daughter together and live an affluent life.

But in movies, such happiness and success usually mask problems or can't last or both, and this is no exception.

We enter Tar's life when it's about to change markedly.

Tar is outspoken and seemingly no fan of concepts like political correctness and the disadvantages women face pursuing careers in male-dominated fields like music. There's a sense that she feels she succeeded, so others can too, and one early scene has her deliver a cogent and scathing takedown of a music student who says he won't play Johann Sebastian Bach's music because of the composer's alleged misogyny.

But Tar isn't some sort of public anti-PC crusader. We learn that although she's capable of generosity and collegiality and charm and is protective of her daughter, there's a selfish and manipulative side to her, too.

Some of that is about keeping up with the hectic and demanding schedule of someone in her position, to be sure.

And some of what's later alleged about her might not be at all true, exaggerated, or at least unproven.

But even granting all this, there's enough to suggest that there's a darkness in Tar, as her name suggests.

READ MORE:

Her relationships with Sharon and with her assistant Francesca (Noémie Merlant) show signs of strain that only increase over time - a new young woman seems to be capturing her attention.

There's also a shadow over the foundation she has to support aspiring female conductors. The activity might seem a generous gesture, out of keeping with her earlier remarks about sexism, but could it be her motives aren't entirely altruistic?

Tar is on screen for the vast majority of the running time of this two-and-a-half-hour-plus movie but Field and Blanchett make her a fascinating figure to watch, even in long scenes like an early interview (a useful way to drop a lot of information without it seeming forced).

And, particularly in the second half, there are suggestions that either there's something supernatural happening or that there are disturbances in Tar's mind - guilt? mental illness? both?

Certainly there are scenes that go beyond the earlier naturalism.

A climactic scene in a concert hall seems a little excessive and the ending might be seen as a comedown or a comeback or maybe a bit of both (is it real?)

While Blanchett is undoubtedly the star, there's a good supporting cast including, adding to those mentioned, Mark Strong, Julian Glover and Allan Corduner.

The scenes of music making - with pieces by Bach and Mahler, among others, are good - Blanchett, it seems, really did play the piano and conduct.

And there's a cold, ominous feeling that runs throughout and is well sustained.

The film seems long at times - how many scenes do we need of Tar running? - but also only gives us tantalising glimpses or leaves us guessing at many points. But then, it's hard to get to know a lot even about most of the real people in our lives.

The audience I saw this with at Dendy seemed engrossed. It's not a movie to take the kids to, or leave them at, but it's one that lingers in the mind and provides plenty to ponder. I'd like to see it again.