Today we’re going back to basics and take a look at two of the most important and least talked about aspects of an acoustic guitar, its body size and scale length.
Before we begin to talk about the characteristics of different body sizes, we should briefly touch on exactly what is going on inside of an acoustic guitar and how it produces sound. If you think back to your high school physics classes you’ll remember that sound is displaced air. An acoustic guitar moves the air in and around itself by way of transfering the vibration of the guitar strings through the bridge to the top of the guitar. As the vibration passes through the top it causes it to flex, bowing back and forth. This bowing pushes the air inside of the guitar. Where body size plays a part is the volume and tone of the resulting note. A smaller body means that the high harmonics are more prevalent whereas a deeper body gives the guitar more bass. A larger top will also lead to a louder guitar as more surface area means more air moving.
I wanted to start with body size because I think it's the more self explanatory of today's two topics. Most players I talk to are pretty familiar with the different body sizes available on the market today and the properties of each.
When deciding on a body size there are two factors to take into account: Comfort and Tone. Comfort is easy enough to understand. The larger a guitar body is the harder it is to make it sit comfortably in your arms or on your lap. Smaller, shallower bodies are much easier to play, causing less fatigue to the players picking hand. They’re also lighter, making them easier to handle on a strap for an entire gig. The difference may only be in ounces, not such a big deal if you’re playing for 10 minutes but every bit counts when you’re standing with an instrument for two hours. Choosing the correct body size is especially important for shorter players who may find the height and depth of a dreadnought or similar body to be too much to handle for any length of time. Taller players may not have to consider this at all when choosing a body size since they may be large enough to be comfortable with any commonly available body size.
Tone is the other factor in choosing the size of your next acoustic guitar. The simplest way to think about it is that the smaller a guitar is the more “delicate” sounding it will be. Small body parlor sized instruments, such as the 0-28VS, are designed to be fingerstyle instruments. Turn of the century parlor tunes and English folk music sound at home on these guitars, especially when played with bare fingers. Your more “American” styles of music like Country, Bluegrass, 60’s Folk and Rock and Roll tend to be played on larger bodied guitars, 000 sized and above (Just another example us liking everything to be big in the U.S.).
When I’m talking to players about guitars, either here at Maury’s Music or on my own time, one thing that I’m always surprised about is how few of them really take scale length into consideration. If you think about it though, it’s really not hard to see why this is. On the surface, scale length measurements don’t seem to be that big of a deal. When a long scale guitar is 25.4” and a short scale is only a ½” shorter at 24.9", it’s easy to overlook the difference as nominal or inconsequential. I’m here to tell you today that it is absolutely not. Scale length plays a huge part in the character of an instrument and should be one of the first things you’re looking at when choosing a new acoustic guitar.
But first, what is scale length? The scale length of an instrument is calculated first by measuring the distance from the nut of your guitar to the 12th fret and then multiplying this measurement by 2. Generally, depending on the manufacturer, a guitars scale length will be somewhere between 24” and 26”. Baritone and bass guitars may be longer than this while small travel sized instruments can be much shorter.
Scale length, along with string gauge, is the determining factor in how much tension each string applies to the neck. In order to tune a string to a specific pitch you need to pull it taut. The longer the string is the tighter it needs to be pulled to reach a specific pitch. Imagine for a second that you have a piece of string (String A), one end in your hand and one end tied to your desk or a table leg. If you pull that piece of string tight with exactly X amount of force and pluck it, maybe while pretending you’re in a jug band, it’s going to give a nice “thunk” sound at a certain pitch. Now imagine you have a second piece of string (String B), this one a couple inches longer than the first. Again you pull with exactly X force and pluck. This time the “thunk” is going to be lower in pitch. To make String B “thunk” at the same pitch as String A, you’re going to need to pull much harder than X. This same principle applies to the strings on your guitar neck.
So now that we know what’s going on the question becomes what does it matter? Let’s say we have two acoustic guitars in front of us, identical in every single way except for scale length. Same top woods, side woods, bracing, body size, strings, etc. Both will also be in standard EADGBE tuning. The only thing separating these two guitars is that one has a 25.4” long scale length while the other has a 24.9” short scale. Exactly .5” different. You get to play both of these instruments back to back to decide which you like better. What can you expect to notice?
The first thing will be that the short scale length guitar is going to be considerably easier to play. Because less tension is needed to bring a short scale guitar to standard tuning, the strings are going to have more slack to them. If we imagine both guitars have medium gauge strings, short scale guitar is going to have 9-10lbs less tension total than the long scale. This means less force is required on the musician’s part to press the strings down, so less fatigue. Keep in mind, we’re not talking about a minute change here. The difference in force needed to fret the short scale guitar will be very noticeable, especially over longer playing sessions. While some players, myself included, tend to gravitate towards long scale guitars because they like the tension, it’s almost impossible to argue with the playability of a short scale. Short scale guitars are like friendly puppies, happy to see you and want to be played with for hours. Long scale guitars are more like a temperamental old hound. Stiffer, grouchier, tougher to get along with, but still ready to be your best friend if you know how to deal with them. Just don't expect them to fetch.
Two short scale guitars enjoying a day at the beach.
Forced dog metaphors aside, the obvious question this all brings up is if short scale guitars are so much easier to play why do they bother even making long scale guitars? The answer is sound, specifically the balance of the lows/mids/highs. Short scale guitars tend to have very pronounced, almost jangly high end without a lot of underlying bass. Long scale guitars have more of a low end response, making the volume more balanced across the tonal spectrum. The choice of which of these two is better is completely subjective, relative to personal preferences and the intended use of the guitar. What should be said though is that, much like the difference between mahogany and rosewood, the tonal difference between scale lengths is not a something you can fake. You can EQ the guitar through the PA however you want but a long scale will never sound like a short scale and vice versa.
One more quick note about scale length: Although this facet of the short vs long scale argument probably affects only a small minority of players, it should be mentioned that scale length should be considered if you’re buying a guitar that you intend to do a lot of alternate tunings on. As we said above, if both guitars are in standard tuning, a long scale guitar has more tension on it than a short scale. This also means that if you plan on downtuning your instrument at all, a long scale guitar can go a lot lower than a short scale can before it becomes unplayable. There are songs I play that require tuning down two steps, a huge jump for an acoustic guitar. If I play these songs on my long scale D-18 the strings still have enough tension at the lower tuning to be playable. If I would try this same tuning on a short scale 000-18 by the time the strings are loosened enough to drop 2 half steps in pitch they are far too slack to play.
Have any questions or something you'd like to add? Be sure to post your comments below!