The guitar is arguably one of the most popular family of instruments. It is a medium-sized string instrument, usually with 6 strings tuned E4, B3, G3, D2, A2, E2. Guitars are traditionally made of wood, with strings that may be of nylon, gut, or steel. These can be played with fingerpicking technique, plectrum, or a combination of both. Guitars project sound either acoustically or through amplification devices. These set of characteristics (size, tuning, material, strings, technique, and sound production) define the different types of guitars: the most common classifications are 'classical', 'acoustic', and 'electric'. Modern guitars were preceded by the Renaissance guitars, vihuelas, and Baroque guitars. Nowadays, the guitar is a primary instrument in nearly all the popular genres.
In classical music the guitar never enjoyed the popularity of the piano or the violin, though it was an affordable instrument and it featured prominently in chamber music. Many composers explored its capabilities as a solo instrument, especially it reached its modern form, at the turn of the 20th century.