The Nashville Number System
The first thing you need to know is called “the universal scale.” Remember roman numerals from grade school math? That's all the universal scale is. In case you don't remember, here are the numerals you'll need, in order, from one to seven: I, II, III, IV, V, VI, VII. Now, remember that “Do Re Mi” stuff from music class back in school? Match it up with the Roman numerals (see TABLE 10-1).
Table 10-1
Okay, let's explain a little and then build a little more. There are seven notes in a major scale, the eighth being the same note as the first, but one octave higher. If you're in the key of A, then “I” or “Do” is an A note. If you're in the key of C, “I” is a C note, and the major scale goes C, D, E, F, G, A, B, and it would line up as in TABLE 10-2.
Table 10-2
What about all that sharp and flat stuff? The C major scale doesn't have any of that. That's why it's the easiest. If you always wrote in C major, that'd be about all you need to know. Since you might get bored with writing in C major for the rest of your life, let's work the rest of the notes in, so that we have more options (see TABLE 10-3). In the music biz, this is called “all the notes there is,” which drives English teachers nuts. What you're about to hear makes classical composers faint, but it
Table 10-3
You'll also notice that the flats are written before the Roman numeral instead of after. This is to separate it from any flats occurring elsewhere in the chord, like a bIII chord with a bVIII note in it. That will actually make sense very soon but, for now, focus on the universal scale (TABLE 10-4). Highlight it, memorize it, let it be your friend.
Table 10-4
As you saw before, the seven notes of the C major scale correspond with the numbers in the universal scale, but what about other keys? Just write the notes under the universal scale in order, starting with the note that's the name of a new key. So for the key of D, the scale would look like the one in TABLE 10-5.
Table 10-5
To find the notes of a D major scale, see which ones line up under the numbers without flat symbols: D, E, Gb, G, A, B, and Db. This works for finding any major scale and, if you know the code, for finding other scales and modes (see TABLE 10-6).
Table 10-6
By the way, the technical name for the major scale is Ionian. All these scales and modes have different sounds and feels. The Dorian mode will give you that “Santana” sound, the Phrygian mode can give the feel of Spanish flamenco music, and the two pentatonic modes are good for rock, pop, and country.
How do I find notes on an instrument?
On guitar, the notes made by the open strings are (fattest to skinniest) E, A, D, G, B, and E. Move up one fret, and you move up one note. So, on the A string, you'd go A, Bb, B, C. Pianos go in order, so ask a friend where the C note is, and you can easily find the rest.
So, if you wanted to find the Mixolydian mode for the key of E, what would you do? First, write down a universal scale, then write “all the notes there is” under it, starting with the key you're in (E). (See TABLE 10-7.)
Table 10-7
Now, use the code for Mixolydian and line up each Roman numeral with the corresponding note in the key of E. What you should get is an E Mixolydian mode in TABLE 10-8.
Table 10-8
But wait, that's not all! You can also use the Nashville Number system to find chords. In a given key, put together the notes that correspond to the following numbers to make the chord shown in TABLE 10-9.
Table 10-9
So, an E major chord is made up of E, Ab, and B. An E minor chord would be E, G, and B, just a one-note difference. This table will come in handy not only for finding chords, but for naming the chords in your songs. Say you've got a song in the key of C and the second chord in the song has the notes A, E, G, and C. Putting the notes in numerical order, you'd have I bIII V bVII. Looking through the codes, you'll see that those notes make a minor seventh chord. There's a lot more useful stuff you can learn about chord construction, but this'll get you started.
When converting chords to numbers, all aspects of the chord (minors, sevenths, etc.) stay the same. If it's a B diminished chord in the key of A, it'll be a II diminished in numbers and a C# diminished in B. This holds true for transposing as well: Chords change names but not essential properties.
Yes, folks, the Nashville Number system slices, it dices, and it even transposes your song to a new key. How? Say you've got a song in the key of D, with the chords D Em A and G, but that's too high for the singer. You need to put the song in the key of B. First, put the chords into numbers with the universal scale (TABLE 10-10).
Table 10-10
So the chords are I, II minor, IV, and V and the chord pattern is I, II minor, V, IV. Starting with the new key, write all the notes under the universal scale so they line up with the chords from the original key and the universal scale (TABLE 10-11).
Table 10-11
The chords in the new key would be B, Dbm, E, and Gb and the chord pattern would be B, Dbm, E, Gb. Once you get familiar with the number system, you won't even have to transpose, you'll be able to play a numbers chart in any key. That's one reason that writers and studio players use this system.
There are many variations on the number system. Each bandleader will have his or her own ways of doing certain things. A look at the charts and a quick conversation before going into the studio to figure these things out can save you from a communication breakdown in the middle of a costly session.

