What Are Scale Forms?
A scale form is a range of frets (usually narrow) within which you can find all the notes of a given scale. So on the standard C6th tuning you can play all the notes of an F major scale using only frets 5, 6, and 7. All the scale tones lie within this 2-fret width -- any further narrowing of this range will result in notes being omitted from the scale.
To see the forms for this scale do the following:
- Select 'C6th-Basic-6' from the Tuning dropdown menu.
- Enter 'F' in the Scale Root field.
- Select 'Major' from the Scale Type dropdown menu.
- Click the Find Positions button.
Notice that there are 7 unique scale forms shown (the first 4 are repeated an octave up, so we don't count the repetitions). This is great. Knowing several forms for a given scale allows you to play comfortably in many areas of the fretboard and makes your playing more fluid. On steel guitar any commonly-played scale generates scale forms all over the fretboard, so we need a way of naming them.
Naming the Forms
The names of the forms are expressed as a positive offset from the scale's root position. It sounds complicated but it's not. Let's look at the above results for the F Major scale. Root position for any F chord or F scale is at the 5th fret. This makes sense: the tuning is based on a C chord in the open position, so we move up 5 frets to get the basic F position. Looking at your search results, notice that the scale form with a lower boundary at fret 5 is called the Root Form because this boundary is at root position for F. Similarly, the form with a lower boundary at fret 8 is called the +3 Form -- it is 3 frets up from root position. A couple of things to note about the root form:
- Root Form isn't necessarily the best or easiest place to play a scale. The form names just give us an easy way to talk about what scale shape we are playing.
- Interestingly, not all scales have a root form. To see this, do a search on the above tuning for the F Natural Minor scale. For the common tunings, minor scales often do not have a root form.
On typical steel guitar tunings there are a surprising number of forms on your fretboard. Usually, there are "primary forms" that stand out—ones that span fewer frets than the others and have a simpler arrangement of notes on the fretboard. These are the ones to focus on initially. Run the F Major scale search again for the Basic C6th tuning and notice the following:
- The +7 Form, +10 Form, Root Form, +3 Form, and +5 Form all have a narrow 2-fret width. Playing the scale there will be easier since the bar is moving at most a 2-fret distance.
- Notice also the logical arrangement of notes with these "prime" foms. The notes collect mostly around two of the frets. This is especially true of +5 Form where all of the notes collect around 2 frets.
- Notice that the +1 Form and +8 Form are much more complex. These forms have a width of 3 frets instead of two and have a more haphazard arrangement of scale tones, making them more difficult to learn (and play!).
- As you gain familiarity playing through scale forms, you'll notice that they usually contain duplicate scale tones giving you a few ways to play the scale. In most cases, you'll latch on to the duplicate that gives you the easiest path to the upcoming scale tone.
The above scale forms scheme is partly based on the CAGED System developed by guitar teachers. There's a lot of information on this system on the web and well worth checking out.