Unlock the fretboard with three notes per string: Learn the 3nps system with 85% less memorization

This was the 8th Fret Science video, uploaded to YouTube on March 27, 2023. As of December 2025, it has received 178k views, making it my #6 video.

Original video description: The three-notes-per-string system is an essential tool for moving freely around the fretboard. This video explains it clearly and reveals how to learn it with 85% less memorization than the usual method. Navigate both vertically and horizontally with confidence, and always know where you are in the scale you're playing.

3nps is not just for shredders!

The three-notes-per-string (3nps) system refers to a way of mapping the major scale and its modes to the fretboard by playing three notes of the scale on each string. It is usually taught as seven separate fingering patterns:

But you don’t need to memorize all of those patterns separately. All of the patterns come from the repeating whole-whole-half-whole-whole-whole-half interval pattern of the major scale:

As a result, there are exactly seven three-note subsequences, with only three distinct fingering patterns that group together conveniently. The patterns starting on the 7th and 3rd scale degrees (the bottom two strings of the pattern) have a half-step/whole-step or 1-2-4 fingering pattern. The 6th and 2nd scale degrees (the middle two strings of the pattern) have a whole-half or 1-3-4 fingering pattern. And the 5th, 1st, and 4th scale degrees (the top three strings of the pattern) have a whole-whole or 1-3-5 fingering pattern. Each pattern occupies a five-fret span before the next pattern starts, except for the pattern that starts on the 4th scale degree, which fills six frets. That means that when adjacent strings are tuned to be five half-steps (a perfect fourth) apart, the patterns almost always stack vertically:

On an “infinite fretboard” tuned in 4ths, this universal pattern repeats vertically, but offset by one fret with each repetition due to the extra sixth fret of the topmost string in the pattern.

In standard tuning, there are in fact four situations when patterns won’t line up vertically on adjacent strings. Because the interval between the G and B strings in standard tuning is just four frets (a major third), any part of a geometric pattern that crosses that boundary is shifted by one fret. When crossing from the G to the B string, you’ll shift one fret toward the bridge, and when crossing from the B to the G string, you’ll shift one fret toward the nut. I call this the “warp” between the G and B strings, because it warps the shapes of patterns that cross it:

The other two situations involve moving between the patterns that start on the 4th and 7th scale degrees. When moving up a string from pattern 4 to pattern 7, pattern 7 is shifted over one fret toward the bridge, and when moving down a string from pattern 7 to pattern 4, pattern 4 is shifted over one fret toward the nut, like this:

Note that these effects can double up if patterns 4 and 7 occur on the G and B strings, creating a two-fret offset between patterns 4 and 7.

With these simple rules in mind, it’s easy to build up a 3nps fingering pattern vertically anywhere on the fretboard on the fly. To do this, we need to remember two things. The first is which fingering pattern starts from each scale degree:

And the second thing we need to memorize is the sequence of scale degrees that begin each string’s pattern. I recommend memorizing these sequences (one for going up and one for going down) as two separate “phone numbers”. Note that you can easily find these sequences by reading up (or down) the first scale degrees of each string in the seven-string universal pattern.

Believe it or not, the information on this page alone is enough to fully recreate all seven of the six-string 3nps fingering patterns!

You can also recreate the “phone number” sequences by counting up and down by threes and wrapping around when you pass 7 going up and 1 going down. This is easy to see if we draw it as a circular pattern:

It is incredibly useful to memorize the 7-string universal pattern as seven pairs of adjacent strings, referred to by the major scale degree of the lowest note. Pair 1 and Pair 5 have the same shape but are made up of different scale degrees, and Pair 1 contains Pattern 4, which shifts the next pattern over by one fret as discussed above.

These string pairs are fantastic for moving horizontally on the fretboard, especially when playing a repeating melodic sequence. When moving up the scale, shift your fingers through the patterns sequentially, wrapping around from 7 to 1 when needed. To move down the scale, just go in reverse order (from 7 down to 1) and wrap around back to 7 when needed.

Since all seven major scale modes share the exact same notes, what distinguishes them is which scale degree is heard as the tonal center. Each mode starts and ends on a different scale degree of the major scale. For example, if you start and end on the second scale degree, you’re playing the Dorian mode. The Mixolydian mode starts on the fifth scale degree. All seven modes are summarized below.

Notice that each scale degree occurs exactly three times in the universal 3nps pattern, once as the first note on a string, once as the middle note, and once as the third note. This means that you can easily play a mode no matter which finger is resting on the tonal center!

It’s incredibly useful to be able to instantly switch back and forth between playing a major scale mode and the pentatonic scale that sits inside it*,* and that’s easy. To do so, you’ll need to learn part of the rectangle and stack system from my video The Only Pentatonic Scale Lesson You’ll Ever Need. In a nutshell, every pentatonic fingering can be split up into two simple geometric shapes. The rectangle, shown in red, is made up of two three-fret intervals on adjacent strings. It gets distorted by the warp between the G and B strings in Form 3.

You’ll also need to recognize that the major and minor pentatonic scales share the same notes, but the roots are in different locations within the rectangle.

To go from a pentatonic (five-note) scale to a mode (seven notes), we have to add two notes, and there are three geometric configurations that occur, one for the Dorian and Lydian modes, one for Aeolian and Ionian, and one for Phrygian and Mixolydian (this doesn’t work for the Locrian mode because it isn’t built around a major or minor pentatonic scale). Each of those three possible configurations occurs in exactly one place in the universal 3nps pattern, so once you’ve identified the scale you want to play, it’s easy to switch over to the 3nps pattern in the correct location. This region in the universal pattern is highlighted below:

To go back to the pentatonic scale, we simply do the process in reverse. Identify the correct two-string set in the 3nps pattern, and then remove the middle notes to switch over to the rectangle. If this doesn’t make sense, I highly recommend checking out The Only Pentatonic Scale Lesson You’ll Ever Need.

To practice the 3nps system, I recommend an exercise I call “running the bleachers”. It involves playing the scale up across the strings, shifting up to the next pattern, then playing down the scale, then shifting up a pattern and repeating the cycle. It’s an effective approach because it forces you to repeatedly switch back and forth between vertical and horizontal movement. To increase the difficulty level, choose one of the seven modes, and whenever you reach the tonal center, play that note twice. For even more of a challenge, try doing this with your eyes closed. Playing without looking has enormous benefits for training your muscle memory and ear!