Tempo decides the speed at which the music is played.
Step-by-step explanation:
The Tempo of a bit of music decides the speed at which it is played, and is estimated in beats per minute (BPM). The 'beat' is dictated when mark of the piece, so 100 BPM in 4/4 compares to 100 quarter notes in a single moment.
A quick tempo, prestissimo, has somewhere in the range of 200 and 208 beats for each moment, presto has 168 to 200 beats for every moment, allegro has somewhere in the range of 120 and 168 beats for every moment, moderato has 108 to 120 beats for every moment, moderately slow and even has 76 to 108, adagio has 66 to 76, larghetto has 60 to 66, and largo, the slowest rhythm, has 40 to 60.