Dave Reed continues his series of music notation for computer literates

What's the value of a written note? No, not the type you write to get out of cross country running, but a note on a musical score. Well if you've ever wondered about such things but never dared ask, keep reading, as what follows should give you a least some of the answers.

The value of notes

In order to show a musician how to interpret a note written on the stave it is necessary to indicate it's length. As you may have already discovered (if you bought last months issue) pitch is related to the vertical axis, where as, all non pitch musical events take place within the horizontal time slot on the staves called bars.

The outline of the head of a note always remains the same shape, but the centre can be either black or white with an assortment of different tails added to the stem. Figure 9 shows the shapes of various notes along with their respective length, starting from a semibreve at the top and descending down to a demisemiquaver. You will notice that the notes are divided down and become increasingly shorter in time. If you can remember this division along with the order of note length you should always be able to arrive at the value of a given note in relationship to another quite quickly, be it a semibreve to demisemiquaver or two immediately adjacent note lengths such as a crotchet and a quaver.

In modern music the semibreve is normally the longest note that is used. However, if you're into ancient scores or religious music, then you will in all likelihood come across a Breve, which is twice the length of a semibreve (pretty logical that eh?). The breve is basically the same symbol as the semibreve but has twin vertical bars added on either side of the symbol.

The value of dotted notes

Notes can have dots placed directly behind them which in has the effect of increasing the length of the written note by one half again of the notes basic value. Therefore a crotchet with a dot behind it would have a value equivalent to three quavers, ie. one crotchet plus one quaver.

It is quite common to find notes that have two dots placed behind them. In such cases the length of the written note is extended by three-quarters of the basic value. For example a crotchet with double dots would be equivalent to a crochet plus a quaver plus a semiquaver.

The value of rests

Periods of silence in music are also very important and have their own set of symbols known as 'RESTS' these are shown at figure 11. Like notes, rests can also be dotted to increase their length, the same rules apply as those for dotted notes.

The bar

A bar is used to sub-divide notes into time slots. A sequence of written notes is therefore divided into bars, each bar having the same length, be they notes or rests. It is important to remember that when transferring notes to the majority of score packages, the notes played in from a MIDI keyboard are checked for length with respect to the current time signature as you insert them. Because of this, it is impossible to end up with a bar that has the wrong length. If the total value of notes added together exceeds the time signature set at the beginning then there will be an overflow of notes into the next bar. It follows that input using score notation imposes a much tighter control over the input of notes and bars and can be very confusing to the new comer. I will be dealing with some of these intricacies and showing some short cuts in a later issue.

Bars are indicated by vertical lines drawn across the staves (bar lines). The length of a bar ie, how many notes can be fitted into it depends on the time signature set at the beginning of the music, and of course the length of the notes. A double bar line is used to indicate the end of each prominent section of a piece and a final bar line (one thin line and one thick one) is used at the very end.

Time signatures

The time signature consists of two figures placed one above the other. The upper one normally indicates how many beats there are in the following bars. The lower figure indicates the value of each of the beats.

A time signature of 2/4 indicates that there are two crochet beats (quarter notes) per bar, each bar therefore is equivalent to four quavers. (Refer back to the chart at figure 9.) 4/4 time is also known as common time and is normally indicated by using the 4/4 symbol, it can alternatively be indicated by a 'C' symbol at the beginning of the piece which stands for common time.

Time signatures which contain either a 2, 3 or 4 as the top number are called 'simple time signatures'. For each of these signatures there is a corresponding compound time signature which has a figure of 6, 9 or 12 as the top number. In compound time each beat is three of the given lengths, for example the compound time for 2/4 time is 6/8 time. Both have two beats per bar but in 6/8 time there would be two extra notes between each beat giving it a completely different tempo.

If a large change in tempo is required then it is possible that the composer will re-set the time signature from say 4/4 time to 2/2 time and possibly back again to 4/4. (Some of Andrew Lloyd Webber's music is known to do this.)

Some compositions use what are known as mixed bars with what appear to be rather odd time signatures. An example of this is 5/4 time which can be thought of as 3/4 plus 2/4 time. The example at figure 14 will, hopefully give you a better idea of how a 5/4 time bar is made up. If you want to try programming in 5/4 time try Dave Brubeck's 'Take Five'.

Bars with accent on the beat

(That sounds like an ad. for a good pub!) We all appreciate that music has a beat (well most of us). When listening to music and tapping your foot in time with the beat, it will probably be that it's the first beat in the bar that you're foot is in time with.

This is because the first beat a bar is usually the strongest, in musical terms it is accented. Accents along with many of the other dots and squiggles will be dealt with in next months issue.

Tied notes

Up until now we have only dealt with individual notes. But, music often needs to indicate notes that last for a longer, and sometimes odd length. This can be done in one of two ways, for example a minim can be shown as a dotted minim which adds up to three crochets. Conversely a minim can be followed by a crotchet and the two tied together.

Any number of notes can be tied together, but it must be remembered that when such ties are shown it is only the first note that is sounded. The length that it is played for (held), being set by the overall value of all of the tied notes added together.

Triplets, fifths and sevenths

So far we have only dealt with notes divided into halves and quarters, but notes are often divided into odd values such as thirds, fifths and sevenths. A note which is divided into three is called a 'Triplet' (there's logic for you!) and is indicated on a score by three notes written within a bracket and a figure '3' placed either under or over it as shown in figure 16.

Notes that are sub-divided into other odd values have a figure such as a '5' or a '7' placed over or under the bracket encompassing the group.

Alternative representation

At this point you may, if you've been looking at a score, start to realise that there is more than one way to represent notes, especially when they are grouped together. The way in which a group is written really depends on the composer or arranger. To help understand some of the variations, figure 17 shows some of the common alternatives.

Start points

Take a look at various pieces of music and sooner or later you will come across one where there seems to be notes missing in the first bar. (Ticket to ride) by Lennon and McCartney is one such. The piece starts and finishes in the middle of a bar. Composers often move a number of notes along to the right of the first bar, with all the subsequent bars appearing correct with the exception of the very last bar (providing there are no repeated phrases). If you take the value of the note(s) from the first bar you will find that the final bar will be minus this value, so that overall everything adds up.

Tempo indication

Music is usually marked in some form or other as to what speed the piece is to be performed. This can be in a form such as 'Marcia' (which is Italian for march) or 'Moderato' (moderately), This helps to give an idea of tempo. Some composers give precise tempo instructions at the beginning of a score with the rate of note lengths per minute, while others are a bit more cagey and indicate a rate given in bpm. (beats per minute) which means that you have to work out the number of beats from the time signature.

It is common for a piece of music to indicate a change of tempo within a specific group of bars, again such indicators are usually in Italian. The reason for all the Italian is that in the early days a vast amount of music originated in Italy, so many of the terms used in todays music still use the Italian language for such things as tempo, volume and style settings. If you're into Italian, you can skip the next bit (and your excused homework!) For the non comprendis among you table 'A' lists all of the commonly used Italian words and their English equivalents.

Well that about raps it up for this session. While you're eagerly awaiting the next issue why not have a go with a score editor, who knows you might be surprised that you can start to get to grips with simple music scores.