Guitars come in two varieties: Acoustic guitar and classical guitar. Both guitars are played in several ways, with the fingers or a plectrum, and also often using an amplifier to make the sound louder. The major difference between acoustic and classical guitars is that the soundboard on acoustic is made out of thin sheets of wood (a 'sound board') while on a classical guitar it is made out of solid wood. They require playing in to get the best sound and they both have a case. Acoustic guitars are easier to play but take longer to get used to and both styles of guitar are made from a variety of materials including plastic, metal, and wood. Acoustic guitars are often associated with folk music, as well as country music, world music, and rock music. They also have a long history of being played in non-western cultures in countries such as Brazil, India, and China. Famous acoustic guitarists include Eric Clapton, Jimi Hendrix, Bruce Springsteen, and George Harrison. Classical guitars are often associated with Flamenco music. They also have a long history of being played in Europe where they were originally developed. Famous classical guitarists include Andres Segovia and Julian Bream. The two types of guitar are similar in many ways. They both have six strings and either nylon or metal strings that are plucked by the fingers or with a plectrum (pick). They are both tuned the same. They both have cases to put them in when they are not being played. They both have frets, although there is one less fret on a classical guitar and it has taller frets. The major difference between the two types of guitar is that acoustic guitars sound better in a larger space than do classical guitars. It is because they have a resonating body that only amplifies the sound while classical guitars also make the sound louder with an amplifier. Acoustic guitars also have a brighter sound so they can be heard further away without being too loud. Classical guitars need to be amplified to play in a large room. In one study students were asked how far they could hear their music when playing an acoustic guitar and then again playing the same piece on a classical guitar. They could pick out the acoustic guitar much more than they could the classical guitar, which meant that people were able to hear the music much louder with an acoustic guitar than with a classical guitar. Looking at the sound of the guitar, acoustic guitars have more bass than classical guitars because these instruments are to some extent hollowed out with a smaller amount of wood. Acoustic guitars also have a more chimney, ringing sound because of the small amount of wood that is used in construction.