Is it really necessary to learn the Number System in Music?

Question

I've been playing the bass for several years now and want to learn how to play jazz. I started out learning classical music because before the bass, I played the violin, so it just came easier for me. In my quest to learn as much as I can about playing jazz, I've come across sites like this that heavily encourage using a number system for learning music. So they say things like 2, 5, 1.

But, I just don't see the point of labeling sounds with numbers instead of using note letters. If you have relative pitch (which I have) you already know the relationship of the notes that you're hearing. Having to change my entire thought process for labeling just seems unnecessary. Am I missing something?

For anyone in here that plays jazz, do you use a numbering system? And in your honest opinion, do I really need to learn this system?

Answer 1

As a bassist who has played predominantly jazz for decades I can say understanding and being comfortable with the number system is necessary if you want to progress to be an advanced player. Here are just a few reasons why:

1. It allows you to associate chord progressions to any key and be able to transpose songs quickly and easily.

2. It is a standard and accepted method of communication between jazz musicians, i.e.: “Does this blues have a 2-5-1 or a 5-4-1 turnaround?”

3. It is part of the vocabulary for the understanding of jazz harmony and theory.

If I were to think about it more I’m sure I could come up with a few more reasons.

Now that’s not to say that it is all a numbers game. We must still be able to relate to notes and chords on a letter system as well and know our 12 keys and cycle of 5ths intimately. As a jazz musician if I’m playing say “Take the A Train” in C I am thinking of the letter chords:

  C / / / |  / / / / | D7 / / / |   / /  / / |
Dm7 / / / | G7 / / / |  C / / / | Dm7 / G7 / ||

At the same time I am thinking:

I - II7(or V/V) - IIm7 - V7 - I - IIm7 - V7

If I have to play it in Ab it’s easy:

Ab-Bb7-Bbm7-Eb7 etc.

EDIT: It has been rightfully pointed out to me by @Lazy that my answer focuses solely on the harmonic aspects of the numerical system. My reason for this is because harmony is so much more often discussed as numbers than melody by jazz musicians. However I do think the numerical system for melody is just as important to learn and understand. There however is a bit of a vagueness to using the numerical system for melody in jazz. The reason I say that is conceptually some musicians may choose to use the numerical system based on the key of the song, i.e. in the key of G, A,B,C is 2,3,4. In the same key over an Am chord some may choose to think of those 3 notes as 1,2,3 of Am. The reason for that is jazz musicians are primarily improvisers. There are many different improvisational concepts but among the most used is to think of notes as the chord and passing tones of the chord being played and not the scale degrees of the key. I am among those who conceptualize melody based on the individual chords. Take “All The Things You Are”. It starts on the VIm chord with a 1 in the melody. To me it is a 3 in the melody of the VIm chord. It helps tie in the melody to the improvisation much better to me. That’s not to say it’s right or better then the other system, just another way of looking at things. This is something to be aware of and keep in mind.

Bottom line, knowing the number system will benefit you for the reasons listed above AND it will make you a better musician in the long run.

Answer 2

Necessary, no, but the number system has become the de facto common language for jazz players. It's convenient, because it describes sounds regardless of the key. Naming the chords/notes themselves is comparatively cumbersome. There is only one "ii-V-I", but there are twelve "Dm7-G7-CM7", "Ebm7-Ab7-DbM7", etc.

If I say to another jazz player "go to the VI chord here" or "this is a ii-V", then it doesn't matter what key we're in, or even if we've transposed the piece, that player understands what sound I'm referring to.

Actually, a stronger statement: if you want to play jazz with anyone beyond a beginning experience level, then yes, you need to learn the numerical language.

Answer 3

From a jazz perspective - although a lot of pop musos benefit from it - it just makes life a lot more simple. You probably are half way there already. Knowing I (1), IV (4) and V (5) of most keys.

Saying to the band 'This has a 1 6 4 5 intro' should mean everyone just jumps straight in, rather than having to say, in key C 'Intro's C Am F G', or key E♭ 'Intro's E♭ Cm A♭ B♭'. It should be almost a given!

Yes, it's pretty well an extension of NNs, which has been around for about 70-odd yrs now, a sort of extension of the RN analysis,but not for analysis purposes, purely for playing. And in jazz, using different keys is commonplace. No need to remind the players that 6 is minor - it's expected, etc. And simple!

Answer 4

It's very useful to know, and if you have good relative pitch, it's a no-brainer - it's just understanding how to verbalize and write down the relationships between pitches that you already understand. It doesn't take much effort.

Answer 5

I play bass in worship team of our church for several years. I have to say it is necessary. I was learning modern piano when I was 8, it was a quick lesson that teach you only in number system, no classic piano stuff. Since then, I was trained to read notes by listening to the melody. I can write down the notes, like 1-1-5-5-6-6-5, for do-do-sol-sol-la-la-sol no mater what key it is. This might make me confused when reading notes in absolute pitch, but the relative notes that I memorized in number system make me easy to change key to suit vocal guy's demand. If you can sing out do-do-sol-sol-la-la-sol when listen to Twinkle, Twinkle Little Star, then the number system is easy to learn for you.

Answer 6

You use the numbering for two main reasons:

• To show the relative relationship of chords, because those relationships function the same regardless of what key you are in. ii V I is basically doing the same thing harmonically whether it's Dm G C or Fm Bb Eb, etc. etc. Numerically we know that progression is roots moving by descending fifths.
• The numbers tell us about chords relative to the tonic. If I write a progression C G, it isn't immediately clear what the functions of the chords are. It could be C: I V or G: IV I. Using the numbers clears up that ambiguity. A C chord isn't just a C chord. C: I is a tonic chord while G: IV is a subdominant chord. Within the context of a key a tonic chord and subdominant chord feel and sound totally different!

Jazz and classical musicians use this system.

If you don't want to learn it, you will be missing a major part of a musician's harmonic vocabulary. Conversations about harmony can be really tedious when someone doesn't know the common terms.

Answer 7

As @John-Belzaguy noted, the number system is efficient and enables musicians to communicate and change keys quickly.

Another reason to use it: it's commonly encountered in studio work and professional rehearsals, both of which may bypass traditional notation entirely.