"Chicago" (Sufjan Stevens)

Sufjan Stevens is one hard cat to pin down.  One minute he's composing impressionistic, sentimental classical pieces about the Brooklyn-Queens Expressway.  The next, he's making trippy, electronic hip-hop as part of the group Sisyphus.  But he's probably best known for his lush, folky song cycles and his widely-publicized ambitions to record 50 albums, each capturing some aspect of the 50 US States.  (Though, he admitted in 2009 that his so-called "50 States Project" actually was a joke/marketing gimmick—albeit a successful one.)
One of the "States" albums, Illinois (2005), is a collection of songs that thematically relate, in one way or another, to the altered titular state.  It's also his best-known, most critically-lauded work.  And rightfully so.  There are touches of Neil Young's bucolic side, the poignant, intimate poetry of Leonard Cohen, and the majestic pop of 60s-era Brian Wilson.
Illinois is lo-fi and DIY at turns, especially in the way it was recorded and produced.  But then the songs have this gigantic, larger than life feel, where everything from clawhammer banjos and out-of-tune upright pianos to thundering timpani and vintage electric keyboards come together in unexpected, grand ways.  
Such is the case with "Chicago," a tune that was used to great effect in the film Little Miss Sunshine (2006).
On the surface, the song is a semi-autobiographical recounting of a road trip to the title city (and New York, too).  But it's not so much a tale about hitting the highway; it's more of an allegory for youthful indiscretions, hasty decisions, and a longing to escape the mundane.  In other words, being in your early 20s.
It's a song that forces you to absorb each individual moment.  At times, it's like listening to a lone singer/songwriter, bearing his soul to a "crowd" of 10 people at a dimly lit coffeehouse.  Then, at the drop of a hat, it leaps to life with mountains of reverberating drums, brass, strings, and a chorus of voices, placing you in the middle of a grand concert hall.
That unassuming-yet-colossal feel perfectly captures Chicago's vibe: Midwestern aw-shucks optimism mixed with Midwestern Broad Shoulders might.
It's a brilliant track off a near-perfect album by a smart, risk-taking artist.