We thank John Vidale for his interest in our paper and raising his concern regarding the seismic source. In Green and Bowers (2008), we concluded that the harmonic signals observed were consistent with electronic dance music (EDM) played at the festival, coupled into the ground through the loudspeaker stands. Vidale disagrees and suggests that steady machinery on the festival site would be a more plausible source.

Vidale uses the example of Figure 5 to suggest that the persistence of the spectral lines across 10 hours of the festival is incompatible with the source being the music, however a...

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