Before we get cracking in the guitar block system, let’s review a basic theory concept: INTERVALS. Why? Because they’re everywhere. When you move from note one to note two, that’s an interval. Guitars are tuned with two particular intervals. Even this guitar block system revolves around intervals. They’re everywhere!
So what is an interval? Well, the term Interval can be defined in five words: The distance between two notes. That’s easy enough, isn’t it? When you move from one note to another note, the distance you traveled to get to that second note is the interval. The guitar block system uses four specific intervals, so let’s talk about them now.
First up is the Minor Second, or, as it’s more commonly known, the Half Step. This is the distance from one note/fret to the very next note/fret. On guitar, that’s moving from, say, fret 3* to fret 4. On piano, this is moving from one key to the very next key.
Next is the Major Second, also known as the Whole Step. One whole step is equal to two half steps, skipping that weird note in the middle. On guitar, this is going from fret 3 to fret 5. On piano, this can be done by playing two white keys and skipping the black key in between.
Now for the thirds. The Minor Third is three half steps OR one and a half steps if you’re so inclined. Using the fret 3 example, this is now moving up to fret 6.
Lastly, the Major Third. This is either four half steps OR two whole steps, depending on how you’re feeling at the time. If you like the fret 3 example, then you’ll be traveling from fret 3 to fret 7. ALSO, the distance between String 2(B) and String 3(G) is a major third.
BONUS: The Perfect Fourth. One of three “perfect” intervals, so named because they give no indication if they’re major or minor. A perfect fourth is five half steps OR two and a half steps apart. With the exception noted above, guitars are tuned in fourths – therefore, the distance between two open strings (except for 2 and 3) is a perfect fourth. Using our favorite example, you would be traveling from fret 3 to fret 8. More commonly, though, you will wind up going from an open string to fret 5 on that same string.
Questions? Ask away in the comments. Otherwise, I’ll see you soon with the first block.
*If you wind up trying these fret 3 examples on string 1(High E) or string 6(Low E), your new buddy is called G. Elsewhere: Fret 3 is C on string 5(A), F on string 4(D), A-sharp or B-flat on string 3(G), and D on string 2(B).