Key characteristic: Acoustic guitarfulness

Optional characteristics: Jangliness; soul; a decent amount of sing-along-ability; a lack of production; whistling; hand-clapping; French lyrics.

In the perfect mainstream indie movie, the gawky male lead is going to get together with the manic pixie dream girl. This requires a montage. This montage requires some inoffensive alt.rock to accompany it, and it must be catchy, guitar-based and almost too twee.

Juno’s ‘Anyone Else But You’ (as sung by stars Michael Cera and Ellen Page) practically defines this, but for other examples, look no further than any artists appearing on those O.C. compilation CDs from a few years back: The Shins (‘New Slang’, Garden State), Elliott Smith (‘Miss Misery’, Good Will Hunting), Leonard Cohen (‘Hallelujah’, too many films to mention), Spoon (‘The Way We Get By’, Stranger Than Fiction), Modest Mouse (‘Little Hotel’, Nick And Nora’s Infinite Playlist), Bright Eyes (‘We Are Nowhere And It’s Now’, Knocked Up) and The Eels (who scores almost all of Yes Man).

Then there's Death Cab For Cutie, whose delightful blend of sombre introspection and jangly hooks have seen their work ubiquitous in indie or wannabe indie movies (Easy A, Shop Girl, Mean Creek, Wedding Crashers) over the years.

Remember: these songs are the definitive sign that you’re watching a ‘Hollywood’ indie movie, so don't scimp on 'em. After all, true indie films – films made for the price of a packet of Hobnobs and a hug – could never afford the rights. Famously, the biggest expense on Kevin Smith’s Clerks was use of an Alice In Chains B-side (‘Got Me Wrong’) on the soundtrack.