Music is the chronological organisation of sounds; that is, making certain sounds at certain times, which make melodic, rhythmic and harmonic sense. The first, most basic concept, is keeping the sounds “in time”. This leads us to some of the first few musical concepts: beat, rhythm, duration & tempo.
Beat is the regular pulse which provides a timeline for the
rhythm to anchor itself to.
Rhythm is essentially repeated patterns of long or short, stressed or unstressed sounds or silences which fit into the main beat.
Duration is the length of notes or sounds or silences which facilitate the rhythm.
Tempo is the speed at which a piece of music is played.