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Acoustic Guitar Body Shapes

Posted by on 3 November 2010


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How does the shape of an acoustic guitar affect it's sound?


A question that people ask me a lot is ...

'How does the size and shape of an Acoustic Guitar affect the tone of the instrument?'

A lot of guitar buyers are blissfully unaware how different guitar shapes give you different tonal 'colors'. A lot of acoustic guitar shoppers aren’t even aware there are different sizes to choose from, as “a guitar is just a guitar, isn’t it?” Well … yes and no.

A guitar is, indeed, just a guitar but there is however, a huge difference in tone depending on what size and body-shape the guitar happens to be. This also determines the style(s) of music a particular instrument is suitable for. These days there are a huge number of guitar shapes available and it can all be quite baffling to the potential buyer, so I’ll try and give a general outline of the history of the most commonly used guitar shapes and what they’re suitable for.

It all comes down to four shapes!!

Yes, all guitars on the market today are a direct descendant from one of four shapes, the Parlor Guitar, the Orchestra Model Guitar, the Dreadnought Guitar and the Jumbo (or Super Jumbo) Guitar. So let’s start with the smallest shape in the guitar family.

Parlor Guitar

The Parlor Guitar is the earliest (oldest) shape of acoustic guitars on the market today. Generally pioneered by the C.F. Martin Co, it's design goes back to the 1800’s. They all have the following features in common: a small, relatively shallow body, a slightly wider finger-board (1 ¾ inches or wider) and a slotted headstock.
I believe the Parlor Guitar is the most misunderstood guitar on the market today. It is generally assumed that a small bodied guitar, like this, will put out a 'small' sound.

Not necessarily so!

A good Parlor will have a strong mid-range focus and round, singing trebles and still enough bass to please most listeners. They tend to have amazing “cut through” power, because of their enhanced mid-range frequencies. I’ve played Parlor Guitars in a room full of Dreadnought players and the little Parlor would cut through the mix like a bell! They are also a favorite choice amongst finger-style players, they have great string to string tonal balance, each note rings clearly and the wider fingerboard makes them ideal for finger-style playing or single note runs.

Mark KnopflerJohn MellencampLinda RonstadtSteve Miller play Parlour Guitars

They also tend to make great recording guitars as they don’t suffer from over-powering bass and other unwieldy frequencies that can so annoy sound engineers. Their only downside is the fact there’s only 12 frets to the body, which may be a stumbling block to a potential buyer, however, most people who play acoustic guitar don’t often venture beyond the 12th fret anyway so it would be a shame to not buy one for this reason. Owning a 12 fret Parlor Guitar can be a very rewarding experience, I’ve owned several and they have been amongst the best sounding guitars I’ve had my hands on. Every reputable guitar manufacturer today will have a couple of Parlor Guitars in their line up, try one of the Taylor parlors, they’re stunning!

Parlour Guitar

Orchestra Model Guitar

Another C.F. Martin design, the Orchestra Model, or OM, as it’s generally called, was really the first 'modern' guitar on the market. Its origins date back to the 1930’s as players called out for guitars with bigger bodies, more volume and guitars with 14 frets to the body. The body size of an Orchestra model is noticeably bigger than a Parlor, however, it’s still got a fairly shallow body depth. This makes it very comfortable to sit down with. Like Parlors, OMs have a well balanced, clear tone with beautiful mids and trebles and strong but not over-bearing bass frequencies. They tend to have incredible 'projection' so they can be clearly heard in the mix.

John Mayer and Eric Clapton play Orchestra Models

An OM has 14 frets to the body so it feels more like a 'modern' guitar. They also have a slightly wider fingerboard, 1 ¾ inches, which makes them a great choice for finger-style playing. This is another guitar that makes a great recording instrument, all frequencies are beautifully balanced and they are generally a joy to play! I have to admit, this is my favorite guitar shape! Various guitar makers manufacture OM shapes, however, they are not always called OM, some manufacturers use the term “Grand Concert”, however, these are all variations on the OM design and have a lot in common with the original OM shape. For example, modern guitars like the Taylor 312, 412, 512 etc…and the Takamine TAN76 and TAN77 owe a lot of their design features to the OM’s of old.

Orchestra Model

Dreadnought Guitar

The Dreadnought is the guitar shape that most people think of when describing an acoustic guitar. It is the most popular shape on the planet, the majority of buyers will claim this to be the shape an acoustic guitar should be! Also dating back to the 1930’s this is the shape that has taken the guitar world by storm. When it was released it was the loudest, biggest thing out there and changed the acoustic guitar market almost overnight. The word “dreadnought” itself is a reference to the biggest, baddest warship in the US navy at the time so they were clearly trying to make an impression with this design.

The Dreadnought has everything a good acoustic should have, it’s loud, it’s got a big voice with whopping bass, and warm, melodic trebles. Some Dreads can lack a bit in the mid-range but that generally comes down to what timbers are used and who the manufacturer is. My guess would be that 75% of acoustic guitar sales in the world are dreadnoughts. It is the shape that appeals most to people. Dreadnoughts have been used by a variety of artists, ranging from the Beatles and the Stones to Pearl Jam, Nirvana and Elvis. In fact, anybody who is anybody in the history of rock and pop music would have played a dreadnought at some stage. It is also the essential guitar for anybody playing bluegrass. It excels at loud single note runs and unlike some small bodied guitars, it handles vigorous strumming extremely well. Which is the reason it’s always been a popular choice amongst rockers. Dreadnoughts generally also have a slightly narrower fingerboard, 1 11/16 inches, which is closer to the size of an electric guitar neck.

Tom Petty, Jack Johnson, John Lennon, Johnny Cash, Elvis Presley, Neil Young and Curt Kobain plays/played a Dreadnought Model

This smaller neck size is another reason this guitar is so popular, it fits most people’s hands!! Funnily enough dreads don’t always make for the best recording guitar, their huge bass response isn’t always conducive for getting a good recorded sound, however, they are the guitar of choice of most live performers and excel at most applications. Notable dreadnought manufacturers: Martin (of course), Taylor and my current favorite, Cole Clark, they make a dread called “Fat Lady”, excellent, affordable dreads with amazing electronics.

Dreadnought Guitar

Jumbo Guitar

The biggest of all acoustic guitars! When Gibson Guitars introduced this shape back in the 1940’s/50’s they labeled it “the King of the Flattops” and with good reason. The Jumbo (or Super Jumbo) is simply huge! Size wise this guitar dwarfs a standard Dreadnought guitar. Gibson set out to outdo Martin in the acoustic guitar market with an even bigger, bolder instrument and they succeeded, at least temporarily. This is the guitar that was made famous by Elvis as he used it on the black and white TV clip of Jailhouse Rock. As indicated by their size, Jumbo guitars sound big! They have huge bass, (and I mean, HUGE!), big mids and clear trebles. However, due to their physical size, they are not the most popular guitar around. For instance, people of smaller stature would have trouble playing this instrument, it’s big!

Emmylou Harris plays a Jumbo Model

Jumbos can sound incredible though, they are excellent for strumming and I’ve seen a few in the hands of serious finger-stylists too, however, their deep, thudding bass doesn’t always make them suitable for the finger-style guitarist. For this reason it wouldn’t be my first choice as a recording guitar either.
So, while they may not be the most all-round instrument of the acoustic guitar family they are seriously cool, have big sound and they look great. This particular size lends itself really well to 12 string options. The Guild company in the 1970’s made beautiful 12 string jumbos that are still sought after today. Today, Taylor make a range of 12 strings with this body-shape and they sound incredible.

Jumbo Guitar
To summarize

Yes, these four shapes pretty much started it all! Every guitar on the market today is a variation on one of these four shapes. A number of manufacturers now put cutaways on guitars to allow access to the upper frets and the above models are all available with cutaways and various electronics options. Modern guitar makers will also deviate from the above shapes by making minor adjustments to body-size, body-depth and overall dimensions. However, these four guitar shapes are the basis of all modern acoustic guitar manufacturing and looking at the assortment of guitars available today, it’s easy to spot where the inspiration has come from.

New Developments, Honorable mention. Grand Auditorium Guitar

One guitar shape that deserves a special mention is the Grand Auditorium (GA) shape. This is a shape pioneered by Taylor guitars. Taylor came up with this design in 1994 and it became an instant hit. In fact this is considered to be the essential Taylor shape. This guitar has the same width and depth as a traditional dreadnought but it’s much more tapered at the waist and looks way more “curvey”, (and more sexy IMO). Taylor set out to design a guitar that, in their words, is “the Swiss Army Knife” of guitars. A guitar that can handle aggressive strumming as well as gentle finger-picking. For those who want a guitar capable of virtually anything you throw at it, this guitar would be it. These instruments have exceptional balance, strong, but not boomy, bass, good mid-range projection and sparkling trebles.

The Grand Auditorium is currently competing with the Dreadnought as the most popular acoustic guitar shape available today. They are excellent recording guitars as well as excellent live performance guitars. The Grand Auditorium shape has been copied by various companies in the last 15 years, to the point where it has now become as standard a shape as the Parlor, OM, Dreadnought and Jumbo. Notable Grand Auditorium Manufacturers: Taylor (they designed it!) Models, 314, 414, 514 etc…, Takamine, they do a series called the Nex Series, all Grand Auditoriums with various timber/electronics options. Cole Clark make a GA called the “Angel”, a beautiful example of what a Grand Auditorium can be. If there ever was a guitar that can do just about anything and handle just about any style, look no further.