The Music
Rhythm
Rhythm is what controls how long or how short each individual not is held out for. Have you ever heard someone use a song as a "secret knock"? I sometimes use the opening notes to the mario theme song as my knock. That time between each individual knock is what create the rythm.
Dynamics
The dynamics control the loudness or softness of the music. You may have seen a little 'p' in sheet music before. This is short for piano, which tells the musician to play softly. In contrast, you may have seen an 'f' in sheet music. This is short for forte, which tells the musician to play loudly.
Tempo
The tempo controls the pace of the song. The higher the tempo, the faster the song. The conductor guides the orchestra to keep an even tempo and to change it when necessary.
