Whether Beethoven or beat boxers, musicians have come to rely on one tool to help them keep time.
The metronome was invented by a friend of Beethoven’s, Johann Maelzel, in 1815. It is used in music to set a tempo, measured in Beats Per Minute, and traditionally has a range of 40 - 208 BPM, roughly the extremes of the human heart-rate. BPM correlates to the human body in other ways, too.
Funk breakbeats, the kind rappers like to rap to, usually range from 80 to 110 bpm, slow enough to be able to enunciate. Music that accompanies body movement is usually faster than that; dance music is typically 110 bpm or more.
Military march tempo is exactly 120 bpm; marathon runners like to listen to music at march speed to keep the cadence from going too fast.
The ideal tempo for disco is 127 bpm. Step aerobics classes use music at disco speed, but advanced classes can get much faster. Modern EDM - electronic dance music - such as techno and house is much faster than disco, often as fast as 140 bpm.
People exercising on cardio machines listen to music between 140-155 bpm. Runners doing shorter distances use very fast music to keep their cadence at maximum; some say the ideal bpm for a 5k race is 180.