Does background music improve or hurt productivity?

Depends on what you’re doing:

Background music has been found to have beneficial, detrimental, or no effect on a variety of behavioral and psychological outcome measures. This article reports a meta-analysis that attempts to summarize the impact of background music. A global analysis shows a null effect, but a detailed examination of the studies that allow the calculation of effects sizes reveals that this null effect is most probably due to averaging out specific effects. In our analysis, the probability of detecting such specific effects was not very high as a result of the scarcity of studies that allowed the calculation of respective effect sizes. Nonetheless, we could identify several such cases: a comparison of studies that examined background music compared to no music indicates that background music disturbs the reading process, has some small detrimental effects on memory, but has a positive impact on emotional reactions and improves achievements in sports. A comparison of different types of background music reveals that the tempo of the music influences the tempo of activities that are performed while being exposed to background music. It is suggested that effort should be made to develop more specific theories about the impact of background music and to increase the methodological quality of relevant studies.

Source: “The impact of background music on adult listeners: A meta-analysis” from Psychology of Music