Music with lyrics about helping is shown to reduce aggression in the laboratory. This paper tests whether the prosocial lyric effect generalizes to reducing customer aggression in the workplace. A field experiment involved changing the hold music played to customers of a call center. The results of a 3 week study suggested that music significantly affected customers, but not in the way suggested by previous laboratory experiments; compared with days when instrumental background music was played, caller anger and employee exhaustion were lower on days when callers were played popular music with neutral, but not prosocial, lyrics. The findings suggest that music influences customer aggression, but that the prosocial lyric effect may not generalize from the laboratory to the call center. © 2014 Wiley Periodicals, Inc.