50 STATES OF FOLK: How Nashville Created the Universal Language of Country Music

If you’ve ever played American roots music, you’ve almost certainly encountered the Nashville number system. It is part of every jam, every lesson, and every fake book. It is the cipher that we use to pass on our aural folk traditions. It is so universal as to feel prehistoric — simply the natural foundation upon which old-time and bluegrass were built.

But in actuality it was a modern tool built to solve a modern problem: the need to keep up with advancing technology and the profit motives of the burgeoning Nashville music industry of the 1950s.

The Creation of Music City

The origins of Nashville as “Music City” can be traced all the way back to the fiddlers and buck dancers of the 1700s. But the title didn’t start to become an identity until much later. After the construction of what would come to be named the Ryman Auditorium in 1892 — soon to be occupied by the country music powerhouse radio show The Grand Ole Opry — Nashville became a hub for country music for the unglamorous reason that it had simply built the infrastructure for it.

As the recording industry grew and music publishing became more and more commercialized, Nashville’s infrastructure grew right alongside it. Soon, record labels like Decca and Columbia set up shop in studios around town and began cranking out records with now iconic artists like Red Foley, Ernest Tubb, and Kitty Wells.

With this explosion in recording came the demand for musicians to play on those records, leading to a new class of “session musicians.” These talented individuals trained themselves not as virtuosos in any single style but rather as jacks-of-all-genres, with the ability to perform and improvise in any style. But there was still one problem: Artists and studio directors still needed to teach these house musicians every arrangement. And studio time is expensive, so they needed these hired hands to come up to speed — literally — as quickly as possible. The musicians needed a shorthand. And so the Nashville number system was born.

The Invention of the Nashville Number System

Before we get into the history of this helpful tool pioneered by studio musicians, let’s quickly review what exactly the Nashville number system is. Originally called basso continuo, which later evolved into figured bass, this tool is known by classical musicians as the Roman numeral system. The Roman numeral system and the Nashville number system are largely the same with some nuanced differences, but we don’t have the time or space to get into that here. For our purposes, we can consider them largely synonymous.

If you are unfamiliar with the system, here are the basics. The first thing to know is that songs are generally thought of as being “in a key,” meaning that there are certain notes that are likely to be included and some that are likely to be excluded. In Western music theory, we have gone on to define chords that go with those notes and patterns. So if someone is playing a song in the key of G major, we know that the “scale degrees” (i.e., the expected notes in that key) will go as follows: G, A, B, C, D, E, F#, G. We can then number these scale degrees, with G as 1, A as 2, B and 3, and so on until we get back to G as 1. We can assign those numbers to their corresponding chords and use them to label and understand the harmonic progression of the song.

The thing is, for any major key, those scale degrees will follow the exact same pattern. To be more specific, it will follow a pattern of moving up a whole step, then another whole step, then a half step, whole step, whole step, whole step, half step. So if someone else were to come along and want to play the song in our example in the key of C instead of G, all they need to do is move everything up and play the same numerical patterns in the new key.

This idea serves as the foundation of the Nashville number system. Early session musicians in Nashville needed to be able to pick up songs quickly, both to play the right rhythms and chord progressions and to be prepared to solo as needed. Writing out every single song in every key that an artist might want to perform them in was wasteful and time-consuming. Plus, session musicians often found those kinds of detailed and scripted charts unhelpful at best, and creatively stifling at worst. Many session musicians never trained professionally and didn’t know how to read music, and those who did felt that it locked them into an arrangement, preventing them from improvising as freely.

So they started just writing down the chord patterns, using the numbers of the notes in the scale like those described above. This method was first pioneered in 1957 by Neal Matthews of The Jordanaires, one of the most prolific groups of session vocalists at the time. Inspired by the shape notes commonly employed by gospel groups in the ’30s and ’40s, Matthews wrote vocal charts by substituting numbers for the shapes, allowing him and his quartet mates to quickly read and understand the songs they needed to record.

A few years later, session stalwart Charlie McCoy noticed the Jordanaires’ unique charts and decided to apply the same numbering system to chords, simplifying the charts for rhythm players. This new system allowed him to quickly lay out an entire song on one piece of paper while listening to the demo for the first time, helping him get up to speed and ready to record without wasting precious studio time. This idea was immensely popular and quickly spread among Nashville’s growing crop of session musicians, soon becoming the second language of Nashville’s musicians.

Modern Usage

The Nashville number system has become  a near universal language not just among session musicians, but within old-time and bluegrass as well. It’s a quick way to learn the harmonic pattern of a song, enabling musicians to jam easily on tunes they haven’t heard or played before, and it’s also helpful for silently signaling to a confused newcomer how to play along. Rather than having to shout out “It goes back to G now!”, jam leaders can instead silently hold up their fingers to indicate what chords are being played, sparing the lost picker the humiliation of being publicly coached and chided.

Nowadays, if you wander into any late-night festival campground or casual kitchen jam, you will no doubt encounter someone quickly running the group through the chords of a song by saying something like, “OK, this one’s a pretty simple 1 4 1 5, but remember it goes to the 4 in the chorus!” With the help of Neal Matthews and Charlie McCoy, you’ll know exactly how to sing along.