Rhythm is fundamental to life. Rhythm can be perceived in the movement of the sun, the moon and the stars. Rhythm makes our hearts tick and defines our breath, in and out. And even the smallest particle in a microbe is part of rhythmic movements. Rhythm in activities is important for culture, for religion, and for sports, schools and hospitals for example. Yet in social situations, social analyses and in social policymaking, rhythm is not considered as a space of analyses or a space of design. City Rhythm explores the potential of using rhythm analyses in the physical world and related data domain for enhancing social safety in neighbourhoods in the Netherlands. Rhythm in the physical world happens both in space as well as in time. Rhythm in data can connect to location (instead of persons), thus circumventing the issue of privacy. However, because the data addresses specific times and places, nonetheless the data still addresses significant social issues.@en