Crazy Heart = [(The Big Lebowski - frat boy yuk yuks) + (The Wrestler/Leaving Las Vegas) + (Hedwig and the Angry Inch - sex change)] x Merle Haggard.
Otis "Bad" Blake (Bridges) not only performs country music (the kind played at run-down juke joints, mind you, not at the Opry or on CMT), he is it, the sad-sack archetype of every one of those songs: drunk, washed-up, penniless, alone. His greatest years behind him, Bad travels the Southwest in his beat-up truck, playing bowling alleys and dive bars. Still famous enough to be recognized by strangers, Bad, who hasn't written a new song in years, coasts on his legendary past, adrift in his own life.
Things take a turn for the better when Bad is asked to give an interview to a Santa Fe music journalist, Jean Craddock (played with great warmth by Maggie Gyllenhaal). Jean, a single mother, becomes charmed by Bad, despite being many years his junior, and the two begin to have a romantic relationship. Bad eventually takes on a paternal role for Jean's son (a role he never played for his own son), and in true Hollywood fashion, with fits and starts, he works at becoming a better man for the two (not without an end-of-second-act-fuck-up to put his reformation in jeopardy, of course.)
The film is as much about music, or rather the lifestyle of musicians, as it is about overcoming addiction. It succeeds more at the former than it does at the latter (which feels rushed and tacked-on). But most of all, it is Bridges who succeeds by making Bad Blake pitiful, loathsome, charming, and (yes) heroic at once -- and all without a whiff of effort.