Abstract: The present invention relates to a system and a method for selecting an audio file using motion data from a mobile computing device connected to or held by a user, the mobile computing device comprising or coupled to motion sensors. The method comprising steps of moving the mobile computing device, obtaining motion data from the motion sensors, computing from the motion data step data based on a number of steps taken by the user in a specific period of time, computing a metronome beat based on the step data and generating a metronome beat file, selecting a stored audio file having a predefined beat parameter matching the metronome beat of the metronome beat file, and playing the audio file.