Topic 2 Musical time on a staff

Music is written on a staff, that is a pattern of five lines and four spaces where notes are placed. A bar is a segment of a staff delimited by vertical lines and containing a given global time value, indicated by the TIME SIGNATURE.

Essentially, a bar is like a box that can contain a limited value of durations as defined by the indication of the fractional value set at the beginning of the song: 

But a value of 4/4 can be obtained in different ways: the number 4 can be the sum of 1+1+1+1, or of 1+1+2, or of 2+2 etc.… Therefore, it is necessary to introduce other values than 1/4 to avoid the rhythm being too monotonous. Here’s a summary diagram: 

Semibreve / Whole Note

Crotchet / Quarter note

Quaver / Eighth note

Semiquaver / Sixteenth note

Demisemiquaver / Thirty-second note

Hemidemisemiquaver / Sixty-fourth note

So, for example, here’s what is possible to get in a time of 4\4: 

As you can see, the note semibreve has a duration of 4/4. Therefore in a 4/4 time, it would be enough to fill a bar by itself.

Conversely, two minims would be enough to fill a bar in 4/4 time. 

Another very important and widely used rhythmic figure is the quaver, whose value is 1/8. It is half of a quarter. To better visualize this relationship, think of a whole apple as a quarter note and the same apple divided into two halves as two eighth notes. So to recap: the added values ​​of two eighth notes (2/8) give a crotchet (1/4) just like the two halves of apples together give a whole apple. 

Let’s add one last rhythmic figure, for the moment: the sixteenth note (1/16), also called semiquaver. Remember that ‘semi-‘ means ‘half’, just like when we say ‘semicircle’ we mean half a circumference. The sixteenth note is therefore half of an eighth note, which means that the added values of two sixteenth notes (2/16) correspond to that of an eighth note. The same fraction 2/16, once simplified, would give 1/8, just as 2/8 would give ¼. Going back to our apple analogy, we could say that if 1/8 represents half an apple, 1/16 represents a slice. So if 4 apple slices form a whole apple, 4/16 correspond, as a value, to 1/4. Let’s see other examples:  

To be thorough, we need to mention that in music there are also silences, called ‘rests’, which like notes have a precise value.
In fact, a  bar could also be filled only with rests. Here is a diagram that summarizes the correspondence between note values ​​and the relative rests: 

And here’s how some of them appear on the staff:

As you can see, if we take the quarter note as the fundamental unit, the other rhythmic figures turn out to be multiples or submultiples of the quarter note. Let’s illustrate it with a graphic example reporting the multiples of 1/4:  

Set the metronome at 72 bpm. Think now of a 4/4 time signature. Synchronize with the speed of the metronome and start clapping at each beat, taking care to accentuate the first beat of the four foreseen. This gives you an example of a 4/4 time signature. Try now with a 2/4 and then with a ¾ always taking care to accentuate the first stroke of each beat: in 2/4 the first of the two and in ¾ the first of the three.

Try repeating the previous exercise by replacing the clapping with the use of a musical instrument. like the piano.

Try to list possible combinations of rhythm patterns for the following time signature, with the only rule that for each time signature you will have to use the most varied possible number of rhythm patterns (refer to the diagram above). 
2/4; 3/4; 4/4; 5/4; 7/4 

Take 4/4 time. Pick a few simple rhythmic divisions like the quarter note, minim, and eighth note. Compose four bars using these divisions liberally. At this point choose a note on the piano (or any other instrument) and try to play solfeggio with the same note the rhythmic divisions you have composed. Finally, choose four notes and assign only one note for each measure. Playing them in sequence you will have an elementary but effective example of musical composition