The Purpose of Number Charts
What number charts are:
A great way of communicating the general harmonic information of music. By using numbers instead of chords, we are getting that info in context of a musical key. This greatly helps our general musical understanding.
Intended to use in conjunction with recordings of music or playing with other musicians. Context is everything in music, and a specific style of music determines how we play and interpret number charts. Playing along with music also lets us hear how numbers sound in a real world context.
The best way to transpose between keys. In fact, the practice of charting out popular songs this way originated in recording studios during the mid 20th century for this exact reason. Studio musicians needed to be able to learn a large volume of music quickly and efficiently and be able to change the key of a song at the whim of the singer. Though the ability to transpose a piece into any key is useful, the real benefit of using numbers is learning to recognize them by ear.
More rhythmically specific than traditional chord charts. By relying on beats instead of lyrics, song structure, form, and rhythm are more clear and concise. Playing a song correctly the first time greatly aids in forming correct muscle and aural memory. It’s even easy to sight read unfamiliar charts because of this, something that is a lot harder to do with chord charts.
The best way to think and hear in context of musical key you are in, at all times. Numbers are a means to an end of greater musical understanding. The result of this shift in thinking means gaining the ability to immediately hear and perceive the vast majority of chords instantaneously, from any genre of music.
What number charts are not:
Suited for every single musical detail. Some examples of music that number charts aren’t suited for: classical music, complex popular music, music primarily melodic in nature, or rock tunes composed mainly with riffs. Ear training is still an essential part of these (and all) kinds of music, there are just too many details that can’t be inferred.
Suited for abnormal or advanced forms of harmony. Too many chords outside of the key, constant modulations, or songs that are harmonically ambiguous are better learned and read by sheet music of some sort. The chords often still share the same key and function together in these cases, but the music is too difficult to surmise from a number chart.
A substitute for a good ear. Numbers compliment playing music by ear, and should never override it. What sounds correct and in the right musical style should never be neglected. A good rule of thumb is to remember number charts strive to meet in the middle of the particular style, theory, and ease of reading.
Set in stone. Because number charts are conceptual in nature, they can often be notated multiple ways. Chordal charts have their own style that strives to be both accurate and easy to read, but other musicians might use different conventions and symbols when making charts. Thinking too legalistically when reading charts or thinking out of context misses the purpose. Number charts are best thought of as a map that is left purposefully ambiguous of details that can be inferred. What can’t be inferred (which chord goes where, for how long) is what’s on the chart.
The entire mission of Chordal is educational: empowering musicians to develop a better ear, better musicianship, and a better musical understanding. Charts are always written with this in mind, and not to be end-all transcriptions that are detail obsessed. Professionals use a variety of methods to learn, chart out, and perform music. No matter the method, musicians that are able to quickly learn and digest many genres of music often utilize and think in numbers.