Electric guitar which lets players "bend" the pitch of notes or chords up or down, or perform vibrato effects. The sound of an electric guitar can be modified by new playing techniques such as string bending, tapping, and hammering-on, using audio feedback, or slide guitar playing. There are several types of electric guitar, including: the solid-body guitar; various types of hollow-body guitars; the six-string guitar (the most common type), which is usually tuned E, B, G, D, A, E, from highest to lowest strings; the seven-string guitar, which typically adds a low B string below the low E; and the twelve-string guitar,
Viola of a viola is wrapped around a peg near the scroll and is tuned by turning the peg. Tightening the string raises the pitch; loosening the string lowers the pitch. The A string is normally tuned first, typically to a pitch of 440 Hz or 442 Hz. The other strings are then tuned to it in intervals of perfect fifths, sometimes by bowing two strings simultaneously. Most violas also have "adjusters"—"fine tuners", that make finer changes. These adjust the tension of the string via rotating a small knob at the opposite or tailpiece end of the string. Such tuning is