4 – Western Music Systems – Pulse, beat, metre, rhythm and tempo
(No one seems to agree on the definitions of these terms. I am presenting them here as I understand them.)
Pulse is the internal timer of music. It is the basic unit of time. It is constant and does not normally change. It runs in the background of every song. Pulse is what you tap your foot to while listening to a song. Like the pulse you feel on your wrist, the pulse of a song is always there. There is neither a beginning nor an end! Pulse is what the bass drum is beat to. A metronome times pulses. Pulses are measured in units called beats per minute (the number of times the pulse ticks in a minute)
Beats is a way of rendering the pulse so that it can be used to space and time the music. That is, beats organise pulses into recognizable and measurable groups, by accenting some and leaving the others unaccented. This pattern of accented and unaccented pulses creates the metre of the song (like the metre of a line of verse is seen as the group of accented and unaccented syllables). Beats are pulses organised into metres. Beats are normally indicated and played by the other (than bass) drums.
Beats are normally organised into units called measures (indicated in the music sheet by bars). Each measure has a certain number of beats in it, one or two of them accented.
Notes of a song are played to the beat. The rhythm of a song can be thought of as how you use the beats to play the notes. Let us say that there are four beats in a measure. A note that you sound can take one beat (say a quarter note or rest), two beats (half note or rest) or the whole four beats (full note or rest). This use of the beat to space your notes in different ways through the song creates the rhythm of the song. Drummers also use various patterns of drumming to the beats to accentuate the rhythm.
[The ‘time signature’ you see in music sheets indicates the number of beats in a measure or bar. For example, a 4,4 time signature indicates 4 quarter notes in a bar. The bottom number indicates the length of the note (1 indicates a full-note, 2 a half-note, 4 a quarter note etc.) and the number above it indicates the number of beats of the half-note or quarter note etc. So, a 4,4 bar has four beats with each beat timing 1/4th of a full note, 1/2 a half-note or 1 quarter note. That is a 4,4 bar can accommodate 1 full-note, 2 half-notes or 4 quarter notes. A 3,4 time signature indicates that a bar can have three beats each accommodating a quarter note. The most common time is 4,4. It is also shown in music sheets with a “C”.]
Tempo is the speed of a song. The higher the beats per minute, the faster the tempo.
There are other concepts like groove, which is a feeling of rhythm you get when listening to rock, jazz etc. It is hard to explain, other than saying that it is a sense of rhythmic patterning that makes you want to dance to the song.
Visit the following pages for notes on particular elements of music.