There are many tunings used for the guitar around the world. There is however, a tuning commonly known as "standard tuning", being (low to high) E A D G B E. This tuning has been considered as the standard since the late 18th century<ref>http://www.guitarnoise.com/faq.php?id=23</ref>. There are alternate tunings commonly used, such as drop-D tuning, open-C tuning and open-G tuning. The tuning of the guitar can have a noticeable effect on the timbrel quality of the notes produced.
In standard tuning, the guitar has a usual range of four octaves, ranging from E3 to around E7 (on a 24-fret guitar). This standard range can be broadened by using basic guitar techniques such as bending a note to raise its pitch, or by using a whammyvibrato-bar arm on an electric guitar to lower its pitch.
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