To a beginner, most guitars tend to look more or less the same, other than the obvious difference between the electric guitars and acoustic ones. You might be forgiven for thinking that, other than this main difference, other features are more used for decoration or show than for any real effect. In fact, although the decoration may well look different, in many cases the materials used to make the guitar, and the way it is constructed, make a huge difference to the sound of the guitar. The voice or tone of a guitar depends largely on the fabrication of the instrument, what materials it is made from and what methods have been used to attach the various parts of a guitar together.
For example, guitars are made from wood, which is a commonly accepted fact even amongst those who know very little about guitars, but the actual type of wood used can make a dramatic difference. Wood is not uniform, and it varies greatly depending on the tree it comes from. Some woods are very light and springy, whilst others are firm and hard wood. The most common woods used in constructing a guitar tend to be ash, pine, sandalwood, rosewood and maple. The harder woods, known as hardwood, tend to be very much more dense. The more dense the wood, the greater, or longer, its sustain, which is the length of time that the sound will carry. On the other hand, the lighter and more springy woods will create a much brighter tone to the guitar.
It isn't just the body of the guitar, with its hollow amplifying chamber, which is important. In fact, the fret board is every bit as important, and the feel of a fret board can vary tremendously from one guitar to the next. The most commonly used woods in constructing a fret board are maple or rosewood. Although these two woods are quite different, they don't tend to influence the sound of the music very greatly when used in the fret board. The main difference, and this really is down to a matter of personal preference, is the way in which it feels. When you consider that your secondary hand will be holding the fret quite firmly, and pressing the strings down constantly, this can make a difference, and so if you are looking to buy a guitar it is a good idea to try out a couple - one of each type.
Of course, these two main elements of a guitar, the body and the fret board, need to be attached, and when you consider the enormous tension that the strings create, this attachment or connection needs to be very firm indeed. There are three different methods used to achieve this. The first is simply to bolt and glue the fret board to the guitar body. This is the easiest method, and the cheapest, and so most introductory models will be manufactured in this way. Although the sound quality isn't affected too much, the main disadvantage of this method is that the sustain is reduced slightly.
Alternative methods of attaching the fret board to the guitar body include the set-neck method, which is where a slot is made in the body of the guitar, and the fret board is slid in. Only glue is used to bond the two together, and because there is much more surface area contact between the two parts, the tone of the guitar is much fatter and warmer, and the sustain longer. The third method is called the neck-through-body style and is actually not really a way of connecting the two separate elements together, since one single piece of wood is used to create the fret board and the centre of the body. The two wings of the body are then connected to this centre section, and this achieves the longest possible sustain, and a truly incredible tone. Unsurprisingly, this is the most expensive method of building a guitar - but as with anything - you get what you pay for.