Listening to music generally makes us more focused by deterring us, for example, listening to our own breathing or the footsteps we make or others make while running.
Music distracts us from pain and fatigue, elevates mood, increases endurance, reduces perceived exertion, and can even promote metabolic efficiency.
It is best to look for music whose cadence and rhythm are in sync with the intensity of the exercise. Thus, the song will have the highest beat when you are at the most difficult point of the routine, and it will go down when it is time to rest and keep your body warm.
For example on Spotify, just type "exercise music" into the internal search engine and it will find different playlists such as: