Acoustic Guitar

The 60-Second Version

An acoustic guitar produces sound purely through a hollow wooden body amplifying the vibration of its strings, requiring no electronics or amplifier whatsoever to be heard. The two dominant body styles are the steel-string guitar, known for its bright, projecting sound favored in folk, rock, and country music, and the classical or nylon-string guitar, known for a warmer, softer tone favored in classical and flamenco playing. Among steel-string acoustics specifically, the "dreadnought" body shape, introduced by Martin Guitars back in 1916, became the dominant shape for the instrument thanks to its notably loud, bass-heavy projection compared to smaller body styles available at the time. The specific tonewood used for an acoustic guitar's top, back, and sides significantly affects its resulting tone, with spruce remaining the most common top-wood choice thanks to its bright, responsive sound under a wide range of playing styles. A guitar's "action," referring to the height of the strings above the fretboard, is another major factor in how an instrument feels and sounds, since lower action is generally easier to play but can introduce unwanted string buzz if it's set too low for the player's technique. Many modern acoustic guitars are built as acoustic-electric models, adding a built-in pickup and preamp to an otherwise fully acoustic instrument, which allows amplification for larger venues without meaningfully altering the guitar's natural unplugged sound.

The Long Version

Why People Care

The acoustic guitar remains one of the most accessible and widely played instruments in the world, and understanding the real differences between body shapes, tonewoods, and string types helps explain why two acoustic guitars that look similar can sound dramatically different in a player's hands.

Glossary

Dreadnought

A large, bass-heavy acoustic guitar body shape introduced by Martin Guitars in 1916, now the dominant steel-string acoustic shape.

Tonewood

The type of wood used in an acoustic guitar's top, back, and sides, significantly influencing its resulting tone.

Action

The height of the strings above the fretboard, affecting playing ease and the risk of unwanted string buzz.

Soundhole

The opening in an acoustic guitar's top that projects the sound produced by the vibrating strings and resonating body.

Acoustic-electric guitar

An acoustic guitar fitted with a built-in pickup and preamp, allowing amplification while preserving its natural acoustic tone.

Go Deeper

• Martin Guitar — Guitar Basics
• The Acoustic Guitar Guide, by Acoustic Guitar Magazine