Alexandre Desplat composed music for Wes Anderson's The Grand Budapest Hotel. Wes Anderson movies make use of their soundtracks. Why not folk music for an imaginary country? (via NPR) transcript and audio are available - go for the audio on this one.
I'm a fan of Desplat's film music - particularly the pieces he wrote for Moonrise Kingdom and the closing fugue which nods to Benjamin Britten's Young Person's Gide to the Orchestra - The Heroic Weather-Conditions of the Universe, Part 7: After The Storm (track 21 on the album)