Guide to Acoustic Guitar Shapes

The acoustic guitar has seen many forms over its long and colourful history. Each shape undeniably has a unique character, in terms of sound, feel and looks.

In this guide, we’ll highlight the most common acoustic guitar shapes you’ll come across - popular models, specifications, and the best for your style!

Do you know your Dreadnought from your Parlour? As contemporary instruments go, acoustic guitars have been around for quite some time. But over the years, they’ve come in many shapes and sizes.

From the small-bodied parlour instruments of American Delta Blues to the ergonomic shapes modern manufacturers, there’s an acoustic guitar for every situation. Let’s take a look at what’s what…

Dreadnought

Pioneered in the early 20th Century by CF Martin, the Dreadnought is naturally one of the largest acoustic guitar types. The term was inspired by the HMS Dreadnought, at the time the Royal Navy’s largest vessel. It’s no surprise then that Dreadnought guitars are typically big bodied, with subtle curves and plenty of depth. The Dreadnought was also one of the first acoustic guitars to feature a 14th-fret neck joint.

Sound summary: booming bass and low midrange. Plenty of volume and depth that ensures that your guitar is heard no matter what.

Looks summary: from the early Martin models, the Dreadnought has always featured wide upper and lower bouts, a wide waist, right-angled broad shoulders and a flat back-end.

Slope-shoulder

The Slope-shoulder (sometimes called the Curved-shoulder or Round-shoulder) is a variation on the classic Dreadnought design. As such, it’s a big-bodied instrument with plenty of depth to its sound. But as the name suggests, it features a softer curve on the ‘shoulders’, where the body meets the neck.

Sound summary: deep low-end and midrange with plenty of projection. The rounded shoulders offer a softer treble response, perfect for hard-hitters.

Looks summary: very similar to a Dreadnought with a wide waist, broad upper and lower bouts, but with softer shoulder curves against the body – hence the name.

Jumbo

The Jumbo was widely seen as the ‘other’ big-bodied guitar. Pioneered by Gibson in the ‘30s to compete with the Dreadnought, it had more pronounced curves with a pinched waist and broad bouts. The broadness of the accentuated curves ensures big volume and big sustain, but the size takes some getting used to.

Sound summary: a Jumbo will provide excellent projection and resonance thanks to the amount of room in the body. The depth of the low-end can give a ‘whole band’ sound; percussive, full-sounding and clear.

Looks summary: broad upper and lower bouts, a comparatively slim waist (though still pretty big), and a rounded back-end.

Auditorium

The Auditorium shape is relatively new compared to its acoustic design counterparts. It sits in the slightly grey area in between big-bodied acoustics like the Dreadnought, and compact offerings like the Parlour. Because of this, there are plenty of variants on the style, and plenty of debate to go with it.

The Auditorium we’re referring to, sometimes known as the Triple-O, features proportions somewhere in between a Dreadnought and a Classical guitar, but is proportionately smaller. The same goes for depth and width – an undeniably comfortable playing experience.

Sound summary: more balanced across all frequencies, in that it has less bass emphasis. GA guitars also produce an overall quieter sound.

Looks summary: as mentioned earlier, somewhere in between a Dreadnought and a Classical guitar. Curved shoulders, a wide lower bout, a pinched waist – but smaller overall, often with a cutaway.

What’s a Grand Auditorium acoustic?

A slightly wider and deeper variation on the Auditorium shape. The expanded dimensions offer a boost in volume and dynamic range without compromising comfort and ergonomics.

Concert

A far more compact offering than the likes of Dreadnoughts and Jumbos. The Concert is also one of the oldest contemporary acoustic shapes that’s still around. Popularised in late 17th Century America, it features subtle curves comparable to a Classical guitar, but with a less accentuated waist. It’s widely considered one of the most comfortable acoustics to play thanks to its small size and depth.

Sound summary: soft and balanced, considered ‘folky’ nowadays. Excellent for softer fingerpicking styles and strumming with quick changes – Gypsy Jazz and so on.

Looks summary: small-bodied, accessible thanks to soft curves and a shallow waist. It also features a flat lower bout.

What’s a Grand Concert acoustic?

Not what it might sound like. A Grand Concert isn’t simply a puffed up Concert acoustic; rather, it features a shallower depth with a slightly wider lower bout. The smaller depth reduces the volume a step further, but makes it a particularly comfortable instrument for smaller people, as well as a great learning instrument for children.

Parlour

The Parlour (often spelled ‘Parlor’ in American English) is generally seen as the smallest acoustic shape of the bunch. Popularised in early 20th Century America (like the Concert), it’s known for its quiet sound, harmonic-rich midrange, 12th-fret neck joint and classic ‘pinched’ shape.

Sound summary: quiet but pleasant, with particular emphasis on the midrange. It’s resonant and plucky, great for folky strumming and fingerpicking.

Looks summary: the Parlour features a very slim design in every respect. A shallow body depth, narrow shoulders and lower bout, but with a subtle waist indent.

Classical / Spanish

Classical and Spanish guitars predate many of the contemporary acoustic designs we’re used to seeing today. As the name suggests, the design originated in Europe and was refined in the late 18th/early 19th Centuries. Legendary Spanish luthier Antonio Torres Jurado is widely credited with defining the design as we know it. Spanish & classical guitars feature 12th-fret neck joints, relatively small bodies (compared to Dreadnoughts) and a deeper body cavity.

Sound summary: Classical / Spanish guitars feature nylon strings, which offer a more rounded sound than steel strings. This, combined with the deep but thin body, provides a rich midrange resonance that handles dynamics very well – listen to Classical guitar music and you’ll know what I mean!

Looks summary: soft, gradual curves leading away from the 12th fret neck joint, a wider neck and a relatively deep body.

Acoustic Guitar Shape FAQs

What’s the difference between cutaway and non-cutaway?

A cutaway guitar features a curved chunk taken out of the main body shape. This is to provide easier access to the upper frets. It also means less wood is used, and there’s less space inside the body cavity. Because of this, the guitar can sometimes be slightly lighter and feature a different tone (often a slightly differently ‘shaped’ midrange).

What’s the difference between Dreadnought and Slope-shoulder?

As mentioned earlier, a Slope-shoulder guitar features softer, curved shoulders on the upper bout against the neck. By comparison, a Dreadnought’s shoulders are usually right-angled with the neck, with the curve being a little more abrupt. Many consider Slope-shoulder guitars to simply be a variety of Dreadnought, because they’re similar in many other respects.

What are the differences between the O/0 acoustic models?

While many people refer to acoustic shapes with names, you’ll often see them labelled with Os and 0s. Here’s what the main contenders mean:

  • OO – referring to the Parlour guitar
  • OOO – referring to the Auditorium guitar
  • OM – referring to ‘Orchestra Model’, aka. Concert

Classical guitar vs Spanish guitar vs Flamenco guitar

While these terms all point to nylon-strung guitars with Spanish origins, there are subtle differences between their meanings – as follows:

  • Classic guitar – built to handle softer sounds and dynamic playing. Often with Cedar or Spruce tops and Rosewood backs/sides.
  • Flamenco guitar – more geared towards volume and percussive sounds. Brighter-sounding tonewoods are often used to ensure projection.
  • Spanish guitar – often used to refer to both, though some classical guitars don’t share the same attributes (for example, using Walnut tonewood).

This isn’t gospel, as many manufacturers experiment with blurring the lines – but it’s a start!

More info

We hope you’re feeling a little more informed about what’s what when it comes to acoustic guitar shapes. With looks, sound and feel in mind, you’re ideally a couple of steps closer to finding the right acoustic guitar for you.

If you’d like to know more about our acoustic guitar selection, check out the full range here. Alternatively, why not check out more of our buyer’s guides while you’re here?

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