The effects of music amplitude on participants' response time to randomly presented, unexpected, visual events were investigated. Ninety participants completed a motor-reaction task without music and with music played at 60, 70, or 80 dBA. Males preferred more intense music than females did, with males selecting a comfort level of 72 dBA and females, 66 dBA. However, participants' reaction time and the total time to respond to a randomly activated red light were independent of gender. All participants responded more quickly when the music was played at 70 dBA (close to their comfort level) than when it played at lower (60 dBA) or higher (80 dBA) amplitudes. It is proposed that people may react more quickly to visual events (e.g., the sudden appearance of a plane on the screen of an air traffic controller, or the unpredictable activation of a car's rear brake lights when driving) with music playing at a volume preset to maintain individual comfort levels against other situational background noise.