A guitarist (or a guitar player) is a person who plays the guitar. Guitarists may play a variety of guitar family instruments such as classical guitars, acoustic guitars, electric guitars, and bass guitars. Some guitarists accompany themselves on the guitar by singing or playing the harmonica, or both.

Although steel-stringed acoustic guitars are now used all over the world, the person who is thought to have created the first of these guitars was a German immigrant to the United States named Christian Frederick Martin (1796-1867). Guitars at the time used so-called catgut strings created from the intestines of sheep.

noun. gui·​tar gə-ˈtär. : a stringed instrument with a flat body, a long neck with frets, and usually six strings that are played with the fingers or with a pick. guitarist.

The energy of the vibrating strings is transferred to the soundboard through the bridge. The guitar's hollow body amplifies the sound of the vibrating strings. The pitch of the vibrating strings depends partly on the mass, tension, and length of the strings. On steel-string guitars, the lower strings are thicker.