Chord Complexity Score
How Blues Warrior grades every blues chord voicing from 0.0 to 10.0 against a real human hand, and why some of them are marked Not practical.
The scale, from Easy to Not practical
Every voicing on Blues Warrior's chord pages wears a badge: a number from 0.0 to 10.0, the name of its band, and a five-step meter. Green is the easiest, red is the hardest, and anything at 9.0 or above is marked Not practical — a shape the notes allow but a human hand cannot realistically hold. The band's name is always printed beside the colour, so the scale reads the same without colour vision.
| Score | Band | What it means |
|---|---|---|
| 0.0–1.9 | Easy | Open strings and small shapes a beginner can hold in the first weeks. |
| 2.0–3.9 | Moderate | Everyday shapes: a small barre, three or four fingers, a short reach. |
| 4.0–5.9 | Challenging | Real practice material — a full barre near the nut, a wide reach, or a muted string to control. |
| 6.0–8.9 | Hard | Advanced: long stretches, four busy fingers and a barre, or several of those at once. |
| 9.0–10.0 | Not practical | Beyond a human hand for most players — a stretch past a large hand's reach, more notes than four fingers and a thumb can hold, or a pile-up of every difficulty at once. |
What goes into the score
The score adds four costs and caps the total at 10.0. Each one is measured from the voicing itself and the instrument it is played on.
- Stretch. The distance in millimetres between the lowest and the highest fretted note, fingertip to fingertip, worked out from the instrument's scale length with the equal-temperament fret rule. A four-fret span is a long reach near the nut of a long-scale instrument and a short one high on a small one, and the score follows the real distance, not the count. Spans under 45 mm cost nothing; the cost climbs steeply past 115 mm.
- Fingers. The fewest fretting fingers the shape needs. The index finger may barre its lowest fret and another finger may flatten across neighbouring strings — whichever way is cheaper for the hand. Four fingers is a full hand; a fifth note is only possible with the thumb over the neck on the lowest string, and costs extra.
- Barres. A barre is strength, not just a finger: it costs more the more strings it holds and the nearer the nut it sits, where the strings are tightest. A second flattened finger in the same shape costs much more again.
- Silent strings. A string that must stay silent between ringing ones has to be damped by a finger while the others sound — each one adds a little.
When a voicing is Not practical
Two things score 10.0 outright, whatever else the shape asks:
- a stretch longer than 165 mm between the outermost fretted notes — past a large adult hand's reach from index to little finger;
- more fretted notes than four fingers and a thumb can hold.
Most of the voicings on a chord page are found by a search that looks for every pattern sounding the chord. The search knows which notes a pattern makes, not whether a hand can make it, so some of what it finds is music no player can hold. Those are the shapes this score marks red, so you can skip them and learn the ones that work.
Worked examples on the Guitar (6-String)
Graded by the same code that draws the badges, on Guitar (6-String) voicings from the chord pages, played on a scale length of 648 mm. Each row is the first voicing in that band among the common chords; patterns run from the lowest string to the highest, x for a string that is not played.
| Chord | Pattern | Score | Why |
|---|---|---|---|
| C Major | x 3 2 0 1 0 | 1.9Easy | 68 mm stretch between the lowest and highest fretted notes; 3 fretting fingers |
| C Major | x 3 5 5 5 3 | 2.2Moderate | 61 mm stretch between the lowest and highest fretted notes; 3 fretting fingers; 1 flattened finger across adjacent strings |
| D Major | x 5 4 2 3 2 | 5.3Challenging | 94 mm stretch between the lowest and highest fretted notes; 4 fretting fingers; a 3-string barre |
| C add9 | x 3 5 7 5 3 | 7.1Hard | 115 mm stretch between the lowest and highest fretted notes; 4 fretting fingers; a 5-string barre |
| G 7 | x 10 9 10 8 7 | 10.0Not practical | Not practical: needs 5 fretting fingers — more than four fingers and a thumb can hold. |
The scale lengths behind the numbers
Stretch is measured against a typical build of each instrument Blues Warrior grades. A shorter-scale model plays a little easier than its score, a longer one a little harder.
| Instrument | Scale length |
|---|---|
| Guitar (6-String) | 648 mm |
| Bass (4-String) | 864 mm |
What the score does not measure
- Your hand. The score assumes an adult hand. Large hands reach further and small hands less, so treat the bands as a guide, not a verdict.
- The music. It grades the shape you hold, not how good it sounds or how fast you can change to it.
- Steel guitars. A lap steel, resonator or pedal steel is played with a steel bar laid across the strings, not by a fretting hand, so its bar positions carry no score at all.