Abstract: A method for adjusting a rhythm of music to match a running rhythm of a person's steps. Even if a running rhythm changes during the same run, the rhythm of the music is changed without changing the sound and the key or the pitch of the music. A music file is converted into a universal PCM format and the fingerprint function is calculated. Repeating patterns are detected in the fingerprint function. Music tempo is estimated using data about repeating patterns. Runner's steps are analyzed using an accelerometer. Then, a special coefficient is calculated in order to either speed up or slow down the music for matching it to the rhythm of the runner's steps.