When I was studying music as a kid, just the word “intervals” would make me groan. “Ah, crap… I get it. It’s the distance between two notes. Whooooo cares!?”
But the longer I played, the more I realized that my sight reading skills and ability to understand the construction of a song all thoroughly depended on what I’d learned about intervals. The longer you play, and especially on guitar, the more you’ll think in terms of intervals than note names.
By the way, if you’re not yet familiar with how to read all the notes on your fretboard, that will help to give you an even better understanding of the stuff we’re talking about here. Check out my easy fretboard reading trick here.
So, what are intervals?
And how can you apply them to your guitar playing to make both reading notation and improvising easier? An interval is simply the distance from the starting note to the ending note. For instance, C to E is a distance of 3 notes (C-D-E) so it’s called a 3rd.
Here’s what each of our basic intervals looks like: (Need a quick refresher on how to read music notation?)
There’s a super easy, two-step trick for spotting these easily on a page.
Step 1: Decide if it’s an even or odd numbered interval.
Take a look at all of the even numbered intervals. You’ll notice that one note is on the line, the other on the space. Now look at the odd numbered intervals. Both notes are either on the line or the space (line, in the case of the graphic above). Just check to see if the notes are the same (both lines or both spaces) or different (one line, one space) and you’ve immediately narrowed your choices down to 3 or 4 intervals.
It’s very easy to eyeball the size of the gap between notes once you’ve got them classified as even or odd intervals. To practice this, open up any sheet music you have lying around and start name the intervals between the notes. You can do this both with chords and with melodies by naming the distance between melody notes.
But if you’re trying to figure out the right notes for a chord or just have a need to find the right notes when they’re not written anywhere, you’ll need a better system for major and minor intervals. Let me first give you a tool that will cut that work in half….
What are reciprocal intervals?
This is a big name for a tiny idea. A reciprocal interval means you just flip the order of the notes. For instance C and F. If we start on C and go up to F we have a 4th. But if we flip them upside down, starting on F and going up to C, we have a 5th.
So what’s the trick? Subtract from 9 and flip the quality (major or minor). Super easy. Here’s another example. G and B. If we start on G and go up to B that’s a major 3rd (G – A – B). But if we start on B and go up to G we get a minor 6th (B – C – D – E – F – G).
Exercise: Figure out the reciprocal intervals for these examples:
1. major 2nd
2. major 3rd
3. perfect 4th
4. perfect 5th
5. minor 6th
6. minor 7th
(Answers: minor 7th, minor 6th, perfect 5th, perfect 4th, major 3rd, major 2nd)
Now that you know how reciprocal intervals work you can learn a system that only takes into account the first three intervals, then use reciprocals to find the others.
2nds – These are simple. A minor second is just a half step (one fret movement). A major second is a whole step (two frets movement)
3rds – The easiest way to deal with these is to count half steps. A minor 3rd is three half steps above your starting note. For instance, starting on G on your 1st string, go up 3 half steps (3 frets) and you’ll be at Bb, which is your minor 3rd. A major 3rd is one extra fret, four half steps higher from your starting note. Our previous example would put you on a B natural. You can, of course, put that note on a different string once you know what it is.
4ths – This is what’s called a “perfect interval” which means it doesn’t have major and minor variations. When you flip it, it becomes a perfect 5th. In a 4th both notes will be natural notes or both chromatic notes. For instance C and F, C# and F#, or Eb and Bb. The only exception is B and F# and Bb and F.
Remember, once you have your 2nds, 3rds, and 4ths you can easily use reciprocal intervals to find your 5ths, 6ths, and 7ths.
Ok, so how do we actually use these intervals on guitar?
Now, finally, how do we apply this with easy to remember patterns on the guitar neck? The good news is that if you have patterns for 3 of these intervals, the other 4 can be figured out on the fly very quickly. As always, memorize as few things as possible and let your brain work through the system to figure out the unknowns.
The 3 patterns you want to know are the 4th, 5th, and octave. They are both very simple shapes and very commonly used in the construction of chords.
Once you have these, we can use a teeny bit of logic to find the other intervals. For instance, if a 3rd is smaller than a 4th, then we can move that 4 down a fret to get a 3rd. The same goes for 6ths and 7ths based on the octave pattern.
Check out the graphic below. The gray dots are the basic 4th, 5th, and octave intervals from above. The red dots show you how to find all your 2nds, 3rds, 6ths, and 7ths by referencing the previous patterns.
As with the others, all of the patterns are moveable to any set of strings, though they change a little when you reach the 2nd string. More to come on that.
For right now, practice these patterns on your bottom three strings. Get used to first referencing your basic 4th, 5th, or octave pattern, then thinking from there to get the interval you’re looking for.
Darn you, pesky 2nd string!
I’m sure you’re aware that, in standard tuning, the interval between the open 2nd and 3rd strings is only a 3rd (G to B) rather than a 4th like all the others. If it weren’t this way, all our fingerings would be so stretched out they’d be nearly impossible to play. The trade off is that we have to make some adjustments to our patterns when we encounter the 2nd/3rd string area.
Mostly it will involve moving the top note up just one fret to adjust our stock patterns. Here’s what to look for:
3rd and 2nd string – Move the 2nd string note up one fret.
3rd and 1st string – Move the 1st string note up one fret.
2nd and 1st string – All your normal patterns work again.
Not too difficult, eh?
Of course, these are not the only way to play these intervals. But they are a good starting point. Get comfortable with these first, then start hunting up some others.
To Come Full Circle… What’s the point?
As I mentioned early in the article, your notation reading skills will quickly come to rely on intervals to move through the music faster than reading one note at a time. Now that you have patterns you’ll be able to read that interval and go straight to your pattern without having to hunt around the neck for a note. It will take a little bit of practice to trust your own head to give you the right answers.
In a more subtle fashion, knowing how intervals work on guitar will improve your phrasing. See, the music is created in the relationships between the notes, not the notes themselves. One note means nothing. Two notes starts to lead your ear in a particular direction. So by reading the relationships of the notes rather than each note in a vacuum, your brain will be attuned to the way the notes work together to make the music. It’s the kind of tiny tweak that can lend a cohesiveness to your playing that you didn’t have before.
I understand that there is a TON of information here. So don’t feel bad if you don’t completely get it all the first time. Work with one section at a time until you get comfortable with it. Then add the next skill. And please feel free to leave me a comment if you have any questions.
And if you’d like more instruction on using intervals to help you master scales, I absolutely recommend Guitar Scale Mastery.
Here’s your cheat sheet!