The mechanics of vibrating strings on a guitar or piano cycling at a certain hertz - 440 for A - combined with E, a dominant 5th. Make the 3rd or 7th flat for a minor key and get a whole new sonic texture - or 'harmony'. 8 notes in a scale, including the octave - which cycles exactly twice or half as much.
A rhythm to drive the process. Bass as a mediator between the beat and the melody.
Ipods, boomboxes, orchestras, to stadium PA's - WE LOVE OUR MUSIC!
What is is about music that has the power to incite a range of emotions from sadness to elation? Where does 'music' come from? Why do certain combinations of notes and chords and melodies appeal to us? What is music exactly? Is God the ultimate author of all things musical?