It can be used to express authority or portray identity.

The very act of playing music defines us, as both performers or listeners.

Its not a happy song.

Its also a clear statement from Llewyn: hes not afraid of sadness.

Oscar Isaac is perfectly morose as the withering soloist, whose partner, Mike Timlin, recently killed himself.

He plucks sorrow out of the air as fluidly as he does his guitar strings.

Van Ronk is, in many ways, a template for Llewyn.

On the scene before Bob Dylan arrived, he found himself overshadowed by the rising star.

And so we get Daves originalGreen, Green Rocky Roadon the CD as well as Oscar Isaacs cover.

But Llewyn is very much his own creation the music in the film makes that clear.

Dinks Song (or Fare Thee Well)is the headline track.

Its another song about love and loss.

He stops, shocked at their uninvited appropriation of Mikes part.

You cant blame him.

But make no mistake: this is Llewyns gig.

But Llewyn wouldnt have it any other way and frankly, neither would we.

Because all of that failure and melancholy makes for a cracking folk song.

And thats what the Coen brothers movie is: a folk song.

Its an exploration of an artists identity and their reliance upon music to express it.

Its something frominside Llewyn Davis.

By not singing, you mark yourself as different from the others.

Conversely, the act of joining in shows youre the same.

Similarity is a big part of the12 Years a Slavesoundtrack.

More on that later.

The full array of orchestral tunes reveals how repetitive it is.

The only other interesting entry isBoat Trip to New Orleans, a haywire mesh of percussion and horrible synth.

Even through that cacophony, though, Solomons theme gently emerges on a sole violin.

Zimmers score is, on its own, not all that impressive.

But that persistent single melody is key to12 Years a Slaves power.

Heres where12 Years a Slavegets interesting: that ability of music to establish a persons position within a world.

Early on, Paul Danos foul plantation boss makes the slaves clap in unison.

Run N***er Runis not included in either of Fox Searchlights soundtrack releases.

The other spiritual in the film, though, appears twice on the commercial album:Roll Jordan Roll.

John Legends rendition is fantastic, but the one with the real weight comes straight from the screen.

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