The guitar is a musical instrument with ancient roots that is used in a wide variety of musical styles. The modern guitar is descended from the Roman cithara brought by the Romans to Hispania around 40 AD, and further adapted and developed with the arrival of the four-string oud, brought by the Moors after their invasion of the Iberian peninsula during the 8th century AD. The acoustic guitar is quieter than other instruments commonly found in bands and orchestras so when playing within such groups it is often externally amplified.

String

Traditionally guitars have usually been constructed of combinations of various woods and strung with animal gut, or more recently, with either nylon or steel strings. The strings are paired in courses as in a modern 12 string guitar, but they only have four or five courses of strings rather than six. The 12-string guitar is also made in electric forms. Instruments utilising "steel" strings may have strings made of alloys incorporating steel, nickel or phosphor bronze.

Acoustic

Guitars can be divided into two broad categories, acoustic and electric:. Guitars may be played acoustically, where the tone is produced by vibration of the strings and modulated by the hollow body, or they may rely on an amplifier that can electronically manipulate tone. Acoustic guitars can also be fitted with electric pickups, and there are some models available today that already have the pickup built into the body. There are several notable subcategories within the acoustic guitar group: classical and flamenco guitars; steel string guitars, which include the flat top or "folk" guitar; twelve string guitars and the arch top guitar.

Electric

Electric guitars can have solid, semi-hollow, or hollow bodies, and produce little sound without amplification. Electric guitars sometimes mount pickups and electronics on the pickguard. Electric guitars have smaller bodies, smaller necks, and it's much easier to press down the strings. Electric guitars require the purchase of an amplifier, and a guitar cable, so they can end up costing a little more. Electric guitars can be made of almost anything, but again, avoid plywood.

Classical

Classical guitars with an extended range are useful for playing lute repertoire, some of which was written for lutes with more than six courses. Classical guitars do not require truss rods as their nylon strings exert a lower tensile force with lesser potential to cause structural problems. Classical performers are known to use them to enable modern instruments to match the pitch of historical instruments such as the renaissance lute.

When a guitar is used to provide rhythmic and harmonic accompaniment for a singer or for other instruments in an ensemble, it is referred to as rhythm guitar. The world's smallest guitar is 10 micrometers long -- about the size of a single cell -- with six strings each about 50 nanometers, or 100 atoms, wide. It is important to make sure that your equipment is in good order and that your guitar is tuned properly. Learning how to play guitar is like learning how to speak a language. The guitar is absolutely beautiful, flawless and plays like a dream.