Types of Acoustic Guitars – Size and Body shapes explained

Guitars come in many body shapes, styles, sizes, materials and number of strings. These different guitars can play different types of music. With so many types of instruments available in the market, it can be really overwhelming for anybody to decide which one to choose. But, the good news is that they all fall into a category somewhere. In this article, we will discuss main types of acoustic guitars in current times.

Conventional acoustic guitar generally has hollow wooden body and six strings. They do not need any external device for amplification of sound. The shape of the guitar and the resonance in it causes sound amplification. But, this form of guitar is not a very loud instrument. Hence, many of the acoustic guitars today have built-in amplification modules and falls in the category of acoustic-electric guitar.

How to Classify Acoustic Guitars

Parameters mentioned below forms the basis of classifying different types of acoustic guitars into various categories.

  • Shape of the Top – Flat or Arch Top
  • Material of the Top – Wood or Steel Top
  • Body Styles – Parlor, Orchestra Model, Grand Auditorium, Dreadnought, Concert, Jumbo
  • Number of strings – 6 or 12
  • Material of strings – Steel or Nylon strings
  • Arrangement of strings – Single or Double.
  • Availability of Resonators - Yes or No.

Flat Wood Top With 6 Strings

We will begin by looking at the most common type of Acoustic guitar. These guitars have flat tops made of wood with six strings made of either Steel or Nylon. Both the variations are trendy and will be covered in adequate details below.

Guitar string types, construction, shapes, gauges, tension and other important aspects related to strings are covered in adequate detail in the following articles.

Sound produced by acoustic guitar is affected substantially by the type of wood used to manufacture it. Popular varieties of woods used are Spruce, Cedar, Redwood, Rosewood, Mahogany and Maple. These tonewoods and their effect on sound, projection, tones, overtones, sustain, balance, dynamic range and other properties of acoustic guitars are discussed in a separate article. 

All solid wood guitars are expensive. Hence, the first compromise, usually done is to have only solid wood top with back and side made of laminates, also known as Plywood. All inexpensive guitars have top, back and sides, all made from laminated wood.

Steel String Guitars

Flat top guitar with six steel strings is also called as the steel string guitar. Their versatility, richness in tone and resonance makes them very popular among the entire spectrum of players.

These guitars are suitable for performances in smaller and medium-sized venues. Use of pickups, built-in mics and amplification is mandatory for larger venues.

Origin Of Steel String Acoustic Guitar

Christian Frederick Martin created the first steel-stringed Acoustic guitar. He was a German immigrant to the United States. Before this, the guitars were having strings made from sheep’s intestines called as catgut strings.

Types Of Steel String Guitars

Steel string guitars are available in a variety of body styles, shapes and sizes to suit the guitarist’s body shape. They range from large body guitars like Jumbo to small body ones like Parlor. Every guitar body style is available in the range of body size from, what is known as ¼ size to full size, in the increment steps of ¼.

More: Kid Size Guitar – Brief Introduction To Guitar Sizes & Scale Length

The table below introduces common acoustic guitar body shapes and sizes, and the nomenclature used to describe them.

Size

Nomenclature

Size Prefix

Body Length (Inches)

Upper Bout Width (Inches)

Lower Bout Width (Inches)

Max depth (Inches)

Concert

O

18 3/8"

10"

13 1/2"

4 1/4"

Grand Concert

OO

18 7/8"

10 7/8"

14 5/16"

4 1/8"

Classical


19 1/8"

11"

14 1/2"

4 1/8" +

Auditorium

OOO

19 3/8"

11 1/4"

15"

4 1/8"

Grand Auditorium

OOOO (previously OM)

20 1/8"

11 11/16"

16"

4 1/8"

Jumbo

J

20 1/8" +

11 11/16" +

16" +

 4 7/8"

Dreadnought

D

20"

11 1/2"

15 5/8"

4 7/8"

Parlor Guitar

While no clear cut size demarcation exists, it is a common practice to refer guitar with bout smaller than 13.5 inches as Parlor Guitar. It is the smallest of the full-size guitar and is particularly useful for anybody wanting to transition from ¾ size to full size or travel.

Parlor guitar was invented and introduced by C. F. Martin in the 19th Century. Popularity of Parlor guitars was at its peak from the end of 19th century to the 1950s, particularly among the blues and folk musicians. They are regaining prominence in recent years for their mid-range tone, portability and historic or throwback vibe.

These are smaller in size than a concert guitar and have an elongated body. This long body shape enhances the volume of this small guitar. Also, some of the modern-day Parlor Guitars have embedded mics and pickups to increase the volume.

Parlor Guitar_2

Their smaller body shape helps in emphasizing tones in the mid-range. These guitars have

  • distinct tones,
  • are easy on the ear, and
  • are very suitable for performances to a limited audience because they are light and have balanced tone.

This makes the parlor guitar ideally suited for acoustic recordings, solos, folk, school blues and slide music. John Mayer has used Parlor guitar from Martin signature series in lot of solo performances.

Auditorium And Grand Auditorium

Auditorium and Grand Auditorium acoustic guitars are between Dreadnought and Concert in terms of size. They are quite similar to Concert in terms of guitar body shape but have a larger lower bout width that is almost same as that of dreadnought acoustic guitar. Lower bout typically has a width of about 15”. But, variation to this width may be found.

It has much narrower waist in comparison to the Dreadnought, making it much easier to hold. Due to this, the guitar firmly sits on the lap without sliding. Auditorium guitar is also referred to as Orchestra and has a classic hourglass figure. With this shape, you can place guitar a lot lower on the leg, making it much more relaxed and comfortable to reach and play. Hence, this guitar is used by guitarists playing folk music or other styles requiring heavy fingerpicking.

They are sometimes referred to as medium-sized guitars and provide a great balance between light touch and volume. The Auditorium was first introduced by Martin in 1920s 

Auditorium Guitar_2

It was the Grand Auditorium (GA) guitar, which put Taylor (currently one of the leaders in acoustic guitar innovations) on the world guitar map.

Dreadnought and Grand Concert catered more to flat pickers and finger stylists respectively. Grand Auditorium delivered on both the fronts. Due to this, it finds favors with the guitarists who want to travel with a single guitar and cover various styles. It performs equally well on stage and in the studio with well defined tone in low, mid and treble range frequencies. GA is second most used acoustic guitar body shape after the dreadnought.

Concert And Grand Concert

Concert-guitars (Size “0” for Martin Guitars) has a small body and a typical lower bout width of about 13”. Its shape is somewhat similar to classical guitar, except for larger lower bout. Due to its smaller size and soundboard, it produces a much quieter sound and rounded tone.

Concert-guitars have much narrower waist widths in comparison with the dreadnought. Hence, it has a more defined sound, that is less bass-heavy.

Concert Guitar_2

Grand Concert-guitars (Size “00”) are more common than the standard Concert-guitars and have a lower bout width of about 14”.

Both these guitars are ideally suited for fingerpicking style with light touch. However, they have a lower volume ceiling, hence, not suitable for hard strumming.

Their small size and rounded shape make them perfect for guitarists with smaller body frames.

Dreadnoughts

Dreadnought is the most widely available and commonly used acoustic guitar body style. They are offered by almost every acoustic guitar manufacturer in the world. Dreadnought is available in budget as well as in very expensive versions.

It has a large soundboard due to wide and less defined waist, deep body with a relatively smaller upper bout. It produces a clean, high volume, pure acoustic sound of wide range with great projection, powerful bass, strong mid-range and bright highs.

Full bass sound is specially desired by the soloists, while large volume makes it suitable to play in the band, where other instruments are competing. Its wide and rich tone can be used in a variety of musical settings to play different genres, like rock, bluegrass, folk, indie, punk etc. It is suited ideally for flat-picking and strumming.

Dreadnought Guitar

Due to its large size, you have to play it more aggressively, to get the soundboard to vibrate. Playing it with a light touch, will not result in desired volume or clarity. Dreadnoughts have a very high volume ceiling, so you can play them harder, to get large volumes without any distortion.

Due to its deep body, dreadnought has much higher ability to sustain any note or chord. Sustained-sound interacts with the strummed notes to create overtones.

However, their bigger size can make it hard to hold and play for smaller people and beginners.

More: Concert Vs Dreadnought

Jumbo

Jumbo guitars, as the name suggests, are the plus-size loud guitars. Legendary musicians like Elvis Presley, Bob Dylan, George Harrison and Noel Gallagher used them. These guitars have large volume, booming & bassy sound with a lot of projection.

Their large size provides a lot of space for sound to reverberate around the body. The space results in a volume which cant be created using any other small body guitar. These are particularly great if you want your guitar to be heard over the crowd.

The first Jumbo guitar was released in 1937. It immediately became famous because of

  • its deep bass sound, and
  • ability to complement other leads styles.

These guitars would not be our top recommendation for smaller people and beginners.

Types Of Nylon String Guitars

Instruments with Nylon strings are quite different from the steel string ones. Steel strings are not suited well to play Classical guitar music like that of Bach, Tarrega, Sor and Brouwer. They have very distinct sound qualities and playing styles. The Nylon string guitars are utilized for playing classical, flamenco and other traditional Spanish styles of music.

On the flip side, nylon strings are not having the tonal resources that are the need of music genres like blues, country, traditional and new acoustic styles that are in vogue today. While some expert players like Willie Nelson, Chet Atkins and Guy van Duser can play these styles on nylon strings, most players simply cannot do that.

These have much more organic sound and wider neck and relies on fingerpicking instead of strumming. The most common type of nylon string guitars are Classical and Flamenco. Some hybrid crossover variations are also available.

Classical Guitars

Also called as the Spanish guitars due to their origin in Spain. They are usually smaller than a dreadnought and have a slimmer waist. The size makes them particularly comfortable to play in the seated position. Their construction and bracing system allows them to be used only with nylon strings.

A good classical guitar always has a light weight construction than other forms of acoustic guitars along with less reinforced necks. As nylon strings transmit much less energy to the top, lighter top and bracing system allows the top to vibrate freely. Light weight translates into comparatively smaller life span compared to other acoustic guitars.

Classical Guitar Image

Classical guitars are smaller than most steel strung ones, but have a flat and a wider neck with broader fingerboards. Hence, there is less interference from the adjacent strings. The neck makes the playing of scales and some of the cord forms, a lot easier for the guitarists. Increased spacing between the strings allows picking hand greater finesse and choice of strokes.

The sound produced by the classical guitar is much calmer, sweet, warm, inviting, comfortable and pleasing to the ears.

Some experts recommend these guitars for beginners and kids as

  • less pressure is required from the fingers and
  • their thicker gauge is easier to target.

More: Classical Vs Acoustic Guitar – A Helpful Guide

Flamenco Guitars

Flamenco is a sub category of classical guitar. It is adapted to play the Spanish gypsy music called Flamenco. Traditionally Spanish Cypress wood is used to make the body of this acoustic guitar. Sometimes Maple or Sycamore may also be used.

These woods give thinner, brittle and crisper sounds in comparison to other classical guitars. The tone should be able to cut through tapping, clapping hands and pounding feet. These instruments sound best when played with forceful strumming in patterns termed as rasgueados. This is quite opposite to classical guitars acoustic features, which is at its best while fingerpicking.

Flamenco guitar

The construction is usually lighter with wider fretboards. Even the strings used in Flamenco-guitars are generally lighter than the traditional counterparts. They are shallower in construction and fitted with violin style wooden friction pegs to reduce the weight of the headstock. This provides balance to the acoustic guitar body making it suitable to be placed in much more erect traditional flamenco playing position.

These guitars are also sometimes fitted with tap plates on the top of the instrument. The guitarists use the tap plates for rhythmic tapping, which is an integral part of the Flamenco style of music. The construction of these guitars needs to resonate the tapping sounds, multi-note playing and fast up and down runs on the neck.

Flamenco is a special purpose acoustic guitar for a type of music. They may not be liked by players for other styles of music. Though, some musicians like them to play country and contemporary styles due to its cutting sounds. Unlike steel string guitar, classical and flamenco burn out with age instead of improving.

Hybrid / Crossover Guitars

The general principle of Hybrid/crossover guitars is

  • They feature many aspects of the classical guitars.
  • Some aspects are modified to make these suitable for electric or acoustic guitarists.

For example, we have crossover guitars, which are identical to classical guitars with the only difference being:

  • In thinner neck profile and narrower width of nut, or
  • Thinner bodies, or
  • Cutaways, or
  • Electronics.

Steel Top Guitars

Steel top guitars are quite like classical guitars. Difference lies in more robust construction and larger body. Their sound quality is outstanding, and the tone is warmer than the classical guitar. The steel used in its construction allows it to be more resilient and durable.

The steel top guitars should not be confused with Hawaiian steel guitars, also known as lap steel guitars. Lap steel guitars are played horizontally. These are plucked by one hand, and the pitch is altered using a slide made of steel or glass.

12 String Guitars

Twelve-string guitars have six regular-sized strings and six thinner strings. Each extra string is placed next to the corresponding regular string, forming six pairs known as courses. Strings in the two high end courses are tuned at the same frequency, while the extra strings in lowest four courses are tuned at one octave higher frequency. To reduce the tension on neck and the body, the instruments are tuned two frets lower than six-string version.

12 string guitar sounds full and resonant. The strings provide louder strumming with increased depth of sound, making it a very good accompaniment for singing with simple strumming. You don’t need to learn any new chords to play it if you already know how to play six-string versions. 

12 string guitar

12 string guitar closeup of soundhole and bridge

It would be best if you played the corresponding strings in pairs and not individually. The sound produced has a semi-chorus effect, which means, that you get a feeling that more than one guitar is being played.

Many notable players of 12 string guitar are Willie McTell, Mark Silber, Lead-belly, Michael Cooney.

Some old blues players adapted their 12 strings to 11, 10 and even 9 strings, to sound different, by leaving tone to three of the upper course strings single. This results in clear melody at the top and highly textured bass.

This guitar is more expensive than the other guitars and is much harder to tune and to play. It is not recommended to go for 12 string, if you are a beginner. Major manufacturer's like Martin, Gibson and Guild did not do production models till the folk boom in the 1960s. 

Acoustic Archtop Guitars

Arch-top design has always been inspired by Violin family instruments, where thick boards are carved into arched tops and backs. So, the soundboard of most archtop-guitars have f-shaped sound-holes or wings fitted on them. Lloyd Loar used them on Gibson's L-5 guitars for the first time. Round hole instruments had low volume, clarity and projection for the Jazz rhythm section.

Instead of an elaborate bracing strut arrangement, arch-tops have only two long struts, known as tone-bars. This makes the soundboard move in up and down direction, resulting in completely different characteristic sound.

Acoustic Archtop

Strings in the archtop pass over the bridge, onto a holding bracket screwed into the end of the guitar. This bracket is called as the tailpiece. Tension in Steel strings in these instruments forces the body joints inwards, as against the flattop, where it tries to pull the joints apart.

Archtops are available in hollow or semi-hollow body versions.

Acoustic archtop guitars have a very focused sound with a deep tone. This sound quality makes it a favorite guitar of most jazz players. It mainly works well in ensembles, when playing lead. Yet, flattop guitar is always a better choice unless you are only interested in playing jazz.

Resonator Guitars

Resonator guitars are different in construction to the other acoustic guitars. The significant difference is the absence of sound hole in these. These guitars are much bigger and have a large, circular, perforated disc in place of sound holes. This disc houses the resonator cone made up of spun Aluminium. The resonator acts like an un-powered amplifier or a speaker.

The presence of resonators results in a very bright and clear sound. Hence, resonator guitars are suitable for performances in large rooms and in open-air.

Resonator Guitars

vintage resonator guitar

Country music artists and blues singers prefer Resonator guitars. Besides, they have found popularity in mainstream music as well.

These guitars are available in

  • square neck versions played on the lap, and
  • round neck version held like any other standard guitar.

You can also play them using glass or metal slides.

Summary

We hope that the above article has given you a fair idea about

  1. Main types of acoustic guitar available in the market, their shapes & body size and
  2. Their salient features.

Learning all the features of a particular acoustic guitar can be a very in-depth process.

Yet, with the information provided, you can take an informed decision about selecting a guitar to suit your interest. In our next article, we will be introducing various types of Electric and Bass Guitars to you.

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