What are Scales?

Scales are simply collections of notes used in music. We call a set of notes a scale when we extract the notes from their musical setting and arrange them in order from a starting point. When left in their musical context, these same notes are called a key. So scales and keys are essentially the same thing. The difference is simply an issue of application—you can think of scales as the theoretical “residue” of music.

Why are they important? Having an understanding of scales will greatly enhance your overall musical development. It will help you to spontaneously improvise solos as well as to develop better relative pitch discrimination (and the associated skill of learning music “by ear”). Furthermore, you will find that different scales evoke different moods, and certain scales are common to certain styles of music.

Eventually, you will learn to recognize the scales purely by their distinctive sounds.

In a nutshell, understanding scales, their interrelationships, and their tonal construction is the essence of learning the fretboard.

Two Sides to the Story

Scales have two different and important aspects: tonality and modality.

Tonality refers to the pitch of the starting note, or “root” note. For example, A major and G major demonstrate two different tonalities. Different tonalities may also be called simply “different keys.”

Modality refers to the relative structure of the pitches based on a given root note. For example, A major and A Phrygian describe two different modalities both beginning on the same pitch of A. Modalities may be referred to as being different “types of keys.”

So any scale or key requires two things to be specified—a starting pitch (tonality), and a type of scale (modality). When a player says a certain song is in the “key of A,” this could in fact mean A major, A Mixolydian, A minor, etc. In practice, the modality—or type of key—is often understood based upon the style.

Further Down the Road

Many styles of music may blend or borrow between modalities. The blues, for example, commonly utilizes a minor pentatonic (or blues) scale played over a major-type background. I mention this simply to emphasize the fact that scales are not inviolate “rules” that must be obeyed. They are simply useful collections of notes that may be blended or modified as needed. But of course, we must first learn the scales separately before we start combining them!