The influence of shape, wood type, and scale on sound, and how to choose them.
An explanation of different types of acoustic guitars!
For those who are dissatisfied with the sound of their current guitar, or for those who want to choose a "no-compromise" guitar as they begin playing seriously, the sound of an acoustic guitar changes dramatically depending on its shape and the combination of woods used. This article will thoroughly explain the differences between each type and how to choose the best one for you.
table of contents
1. First things to know! The three main categories of acoustic guitars.
1-1. Steel-string guitar (folk guitar)
1-2. Classical Guitar (Nylon String Guitar)
1-3. Electric Acoustic(Electric-acoustic guitar)
3. [By Body Shape] Acoustic Characteristics and Suitable Playing Styles
3-1. Dreadnought: Rich bass and powerful sound
3-2. Fork / OM / OOO: Responsiveness and balance
3-3. Parlor / New Yorker: Small and delicate sound
3-4. Jumbo: Overwhelming volume and presence
4. Differences in overtones and character by type of wood (tonewood)
4-1. Top wood: Spruce and cedar
4-2. Side and back materials: Mahogany and rosewood
4-3. The decisive difference in sound between solid wood and plywood.
5. [Playability] The Secrets of Neck Scale (String Length) and Nut Width
5-1. Scale length and tension
5-2. The effect of nut width on fingering
6. How to choose the perfect acoustic guitar for you
6-1. Singing and playing guitar, mainly strumming.
6-2. Solo Guitar - Fingerstyle
summary
1. First things to know! The three main categories of acoustic guitars.
Before we delve into the fascinating world of acoustic guitars, let's first clarify the three main categories that form the basis of this classification. Even guitars that look similar at first glance can have vastly different playing characteristics and suitability for different genres, depending on the material of the strings and the presence or absence of electrical mechanisms to amplify the sound.
1-1. Steel-string guitar (folk guitar)
Currently, when people refer to an "acoustic guitar," they are most commonly referring to this type with steel strings. From strumming with a pick to delicate arpeggios played with fingers, it is used in all kinds of popular music, including pop, rock, country, and blues.
It features the bright, long-sustaining high frequencies characteristic of steel strings, and powerful low frequencies. The neck is relatively thin, making it suitable for playing chords.
1-2. Classical Guitar (Nylon String Guitar)
Classical guitars, also known as gut guitars, are strung with nylon strings (in the past, sheep intestines, or gut, were used). Compared to steel strings, they have lower tension, and their greatest characteristic is that they produce a rounded, warm, and soft tone when plucked with the fingers.
It is primarily used in classical music, bossa nova, and flamenco. The neck width (nut width) is around 50mm, which is wider than that of a steel-string guitar (around 43mm), and the fretboard is made flat, making it easier to play complex single notes and perform the fingerings specific to classical music.
1-3. Electric Acoustic(Electric-acoustic guitar)
These models incorporate microphones or sensors called "pickups" inside the body or under the bridge of steel-string guitars or classical guitars, allowing them to be directly connected to guitar amplifiers or PA systems to produce louder sounds.
The natural sound (sound without an amplifier) resonates like a regular acoustic guitar, but a preamp is essential if you want to output the acoustic guitar's sound without it getting lost in a live stage or band ensemble. Recently, models equipped with high-performance preamps that do not compromise the natural sound have become mainstream.
Staff comments
Even though we use the single term "acoustic guitar," the choices vary greatly depending on the genre of music you play and the sound you want to produce!
They're all so fun, full of elements that will get you hooked and unable to stop!
If you have a vague desire to "try playing an acoustic guitar," I recommend starting with a folk guitar!
2. How the shape and wood of an acoustic guitar affect playability and sound
Now that we understand the broad classifications, let's delve deeper into the "steel-string guitar," which offers the most options and is the most complex.
An acoustic guitar is, in a sense, a "resonating box made of wood." The vibrations of the strings are transmitted through the bridge to the soundboard (top wood) of the body, and these vibrations resonate within the box before emerging from the soundhole. Therefore, the "size and shape (body shape)" of the box determines the volume and richness of the bass, while the "type of wood (tonewood)" that makes up the box determines the character of the sound (how it contains harmonics and the hardness of the sound).
Intermediate players looking for a second guitar often feel that "my current guitar is good for strumming, but the sound is muddy when I play solo guitar," precisely because the combination of "shape" and "wood" is a mismatch with their playing style.
3. [By Body Shape] Acoustic Characteristics and Suitable Playing Styles
The body shape (shape and size) not only affects the visual impression but also determines the physical "sound potential" of the guitar. Let's look at four representative shapes.
3-1. Dreadnought: Rich bass and powerful sound
The "Dreadnought" is practically synonymous with acoustic guitars. Developed by C.F. Martin in 1916, it was named after the massive British battleship HMS Dreadnought. It features a shallow waist and a large body that produces an overwhelming volume and a rich, resonant bass tone. It excels at powerful strumming with a pick and provides excellent accompaniment for vocals in singer-songwriter performances.
The Martin D-28, among others, has become a global standard for this style.
List of Dreadnought-type Acoustic Guitars in Stock
3-2. Fork / OM / OOO: Responsiveness and balance
The "OOO (Triple O)" or "OM (Orchestra Model)" shape is slightly smaller than a dreadnought and has a deeper waist on the body (in Japan, it's also called a folk size). Because of its smaller body volume, it doesn't have the same powerful bass as a dreadnought, but in return, it has an excellent balance from low to high frequencies, and the sound of each string is clearly separated.
Furthermore, its fast "response"—the time it takes for the sound to come out after plucking the strings—makes it extremely popular for fingerpicking and solo guitar, where subtle nuances can be expressed through finger touch.
000/OM series acoustic guitar inventory list
3-3. Parlor / New Yorker: Small and delicate sound
Even smaller than the OOO style are guitars known as "parlor guitars" or "New Yorker guitars." Historically, they were created in the late 19th and early 20th centuries for playing in home parlors (living rooms) rather than large concert halls.
While the volume is modest, its charm lies in its warm, nostalgic tone with a prominent midrange. It's perfect for blues fingerpicking or casually strumming at home, and it also has the practical advantage of being easy to hold, even for smaller individuals.
List of parlor-size acoustic guitars in stock
3-4. Jumbo: Overwhelming volume and presence
A "jumbo" size guitar has a wider body than a dreadnought, and a more pronounced waistline. The Gibson J-200 is a famous example of this size.
The large body allows plenty of air to resonate, resulting in a crisp, sharp sound when strummed and a tremendous volume. It is ideally suited for country music and for providing rhythm in acoustic bands.
4. Differences in overtones and character by type of wood (tonewood)
Once the body shape is decided, the next step is to look at the "wood (tonewood)" that makes up that box. The body of an acoustic guitar is mainly made up of a combination of "top wood (soundboard)" and "side and back wood (side and back panels)".
4-1. Top wood: Spruce and cedar
The top wood acts like a speaker cone, initially receiving and amplifying the vibrations of the strings. The most popular choice is spruce. It offers a good balance of hardness and lightness, producing clear, crisp highs and a wide dynamic range (the range of volume).
Playing it hard produces a powerful sound, while playing it softly produces a delicate sound. On the other hand, it is often used in classical guitars, and some steel strings are also used.RecruitThe wood used is cedar. It is softer than spruce, resonates well from the first strum, and is characterized by a warm, round tone. Because it produces a rich volume even with a light touch, it is a popular wood among fingerpickers.
4-2. Side and back materials: Mahogany and rosewood
The side and back woods determine how the sound produced by the top wood is shaped and reflected within the body of the guitar. Understanding the difference between the two major woods, mahogany and rosewood, is crucial for intermediate players. Mahogany is a light and soft wood with a distinctive midrange. It has a fast attack and a crisp, dry, and clear sound. Because it has few unwanted overtones, it doesn't interfere with vocals, making it very suitable for singer-songwriters.
In contrast, rosewood is a heavy and hard wood. It produces strong bass and treble frequencies (a so-called "scooped" sound) and creates complex and rich harmonics. The lingering reverberation (reverb) that spreads softly after playing is beautiful, and even when playing single notes in a melody, the sound has weight and luster, making it highly recommended for those who prefer solo guitar. You can really feel the difference in high-end models from manufacturers like Yamaha, which are renowned for their commitment to wood quality.
List of Yamaha acoustic guitars
4-3. The decisive difference in sound between solid wood and plywood.
Not only the type of wood, but also the "structure" directly affects the sound. Plywood (laminate), which is made by layering and gluing together multiple thin wooden boards, is strong and inexpensive, but the adhesive layer hinders vibration, so there are limitations to its resonance.
On the other hand, "solid wood" tops, cut from a single piece of solid wood, fully utilize the inherent vibrational characteristics of the wood, producing rich volume and overtones. In particular, having a solid wood top is said to be the minimum requirement for good sound.
Furthermore, "all-solid wood" guitars, with their solid sides and back, allow you to experience the unique joy of a musical instrument as the sound develops over time through "aging," where the wood dries and becomes more resonant as you play it more.
Staff comments
When choosing an acoustic guitar, the time spent considering the materials, body shape, and other specifications is both challenging and enjoyable!
The above are merely trends, and there is no definitive statement that "this cannot be used or is unsuitable for this genre."
Don't overthink it; just pick up whatever catches your eye, and you'll be fine!
5. [Playability] The Secrets of Neck Scale (String Length) and Nut Width
5-1. Scale length and tension
The scale length refers to the distance from the nut (the point where the strings rest on the headstock) to the saddle (the point where the strings rest on the bridge). It is mainly divided into "long scale (regular scale)" (approximately 645mm or longer) and "short scale" (approximately 628mm or shorter).
Long-scale guitars have higher string tension, resulting in a punchy, punchy sound that doesn't easily become muddy even when down-tuned. On the other hand, short-scale guitars have lower string tension, requiring less pressure to press down on the strings, making techniques like string bending easier. In terms of tone, they tend to have a slightly smoother, sweeter tone.
5-2. The effect of nut width on fingering
The nut width determines the feel of the neck and the spacing between the strings. While typical steel-string guitars have a nut width of around 43mm, OM models designed for fingerpicking often have a slightly wider nut width of 44mm to 44.5mm.
This difference of just 1 to 1.5 mm makes a crucial difference when playing complex chords or when you accidentally touch an adjacent string and stop the sound.
Staff comments
Scale length, nut width, and neck shape are important factors that affect both playability and sound!
Prioritizing sound characteristics over playability would be counterproductive, so it's best to first find a combination that's easy for you to play!
6. How to choose the perfect acoustic guitar for you
6-1. Singing and playing guitar, mainly strumming.
If you're going to accompany a song with chord strumming using a pick, the classic combination is a "dreadnought + spruce top + mahogany sides and back."
The rich bass provides a solid rhythmic foundation, while the clear midrange of the mahogany body doesn't interfere with the vocal range. Alternatively, choosing a short-scale model like the Gibson J-45 will give you a crisp, percussive sound.
6-2. Solo Guitar - Fingerstyle
For solo guitar playing where you simultaneously play melody and accompaniment with your fingers, one of the best options is an "OM or OOO shape + spruce top + rosewood sides and back."
The responsive body shape picks up even the slightest nuances of touch, and the rich overtones of the rosewood beautifully adorn the melody line. Choosing a model with a wider nut width of 44mm or more will increase the accuracy of your fingering.
summary
Acoustic guitars are created through a combination of factors: differences in response and volume due to body shape, differences in sound and character due to tonewood, and playability due to scale length, etc.
However, the visual appeal of each acoustic guitar is also important.
It's also a good idea to find a special instrument that perfectly suits your desired sound and playing style.
First, choose based on your visual preference, and then consult with our staff to see if it suits your style. This might help you find the perfect pair!
Acoustic Guitar Inventory List
Author of this article:Mochizuki (Advance Guitars staff)
In his personal life, he mainly plays electric guitar. Leveraging his boundless love and interest in instruments—which leads him to continue playing even during work breaks—he showcases the charm of acoustic guitar with Advance Guitars' top-notch strumming technique.
Qualifications and experience: Four years of experience as a musical instrument appraiser.
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