Originally submitted by George Badland on Mon, 21/12/2015
Whilst putting and arrangement into my music programme there were several places where notes with double dots were required. Consequently I thought a blog on dotting may be of interest to some.
If you take any note say, a minim, (the one that looks like a zero with a stick attached), it's normal time value would be two beats in a bar of 4/4 music. By adding a dot to the note, it's time value is increased by half and therefore would became equal to a minim plus a crotchet or three beats.
If a second dot is added, the note value is increased by a further amount, but this time it will be half of the crotchet that was added by the first dot i.e a further 1/2 beat. The resulting value of this double dotted minim would be a minim, plus a crotchet plus a quaver or 3 1/2 beats.
A third dot (very rarely seen, and never in barbershop to my knowledge,) would add what is known as a semi quaver or half the value of the quaver. i.e. 1/4 of a beat making a total of 3 3/4 beats
Clearly the more dots that are added, and there are no limits to the number, the more difficult it would be to sight sing or sight play, so two dots is usually the practical limit.
Why do we use dots at all? Well it is simply a short cut for those writing out the notation and stems from the time when all notation was written out by hand. It saves time, ink and space on the score.