Synth-pop band Capital Cities has plenty of songs on its debut album that it wants to promote as singles—if only radio programmers would allow it.

The band's hit, "Safe and Sound," is the only song most fans have heard: it has been playing on the radio for more than two years. And because so many listeners now know the song, which peaked last year at No. 2 on radio's Top 40 chart, stations are afraid to take it out of rotation.

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