I feel like there is a bit of distance in between us friend! If you and I were musical notes you might say it’s an interval! :). You are probably wondering why you need to know this nonsense about intervals, so I will tell you. Music can be described mathematically (as I am sure you know). This is not higher level calculus or anything but it is pretty cool to know.
A basic understanding of this concept can cement your musical understanding of notes, chords, songs and ultimately music! The concept of an interval is relatively simple, but it’s impacts are far-reaching in terms of music. “What is a musical interval?” Let us find out!
Intervals – What You Need To Know.
If you are wondering why there is a picture of a measuring tape above it is because an interval refers to the distance (I thought that was pretty clever, right?). More specifically the interval refers to the physical distance between two notes. This distance is heard as a change in pitch.
The smallest unit of intervals on the guitar are called Semitones. On the guitar, every fret represents a semitone. Two Semitones make up a Tone. another name for Semitones if a half step and therefore two half steps make up a Whole Step (also know as a Tone).
We most commonly see intervals noted by its quality and scale degree, for example, Major 3rd or Diminished 7th. Quality can be Major, Minor, Augmented, Diminished or Perfect. The Scale degree is the number taken from a diatonic scale. Different numbers of semitones between two notes result in a differing interval number.
Diatonic intervals are two notes from the diatonic scale (this scale has five tones and two semitones). Chromatic intervals are between two notes of the chromatic scale (this scale has all the 12 of the tones and semitones of the musical alphabet.)
If two notes are played together the interval can be called vertical, if one follows the other it is called successive. It may help you to know that your guitar tuner probably measures pitch in cents which is basically a hundredth of the pitch of a semitone so divide the space between two frets into 100 and you have a cent!
Interval Background – The Reason For Intervals
When you play the guitar you change the notes that you play right? Have you ever thought about how it actually works though? I mean why does moving your finger along a string change the sound of the note? The answer is quite a simple one! If you take a look at any string on your guitar (let’s take the Low E string for example), and look at the entire string.
You can see that it effectively “ends” at the Nut (near the neck) and at the bridge (close to the pickups or soundhole). You can also see the “playable” area also know as the fretboard. The reason I am pointing all of this stuff out because now that you can see that both ends of the string are effectively held at two points you can understand what I will be saying next.
When you tune a Guitar String, you are increasing or decreasing the tension on the string to achieve a specific Pitch. When you turn the guitar Tuning keys you can actually see the string winding or unwinding which increases or decreases the tension respectively.
This Pitch is directly linked to the length, type of material and thickness (diameter) of the string. These factors combine to give you a certain pitch when the string achieves the correct amount of string tension (this is known as being in tune). We will focus on the string length in the next paragraph to really understand its importance.
String Length – Just Keeping My Word!
The length of the string is one of the factors affecting the sound produced from it. The complicated version is that varying string lengths oscillate (or vibrate) to different degrees. What I mean by this (and you can actually see this happen on the thicker strings) is that when you pick, pluck or strum the strings it looks like one string turns into many strings right?
This is the string moving towards and away from rest position or for the more advanced people here, the crests and troughs created by the longitudinal wave This wave vibrate through the body which disrupts the air around it and produces the sound that we hear.
I will stop there before I write a textbook on the science behind music, but all you need to know is that the sound you hear is directly related to the length of the guitar string.
Pulling It Together – Finally Getting To The Point!
So why have been making you read all of this? Simple to blow your mind (or not, we’ll see)! Now that you know all of this, you can understand that when you fret a note, you are actually changing the length of the string! Crazy right? It would actually be more accurate to say that you are changing the vibrating length of the string.
What this means to you is that by shortening the vibrating length of the string ( all of the string after your fretting finger) you are actually raising the pitch. A fun fact for you, when you go to the 12th fret of any string fret it is exactly double the pitch of the open string (an octave).
If you guessed that the reason is that the 12th fret is exactly half the length of the playable string length, then you are right on the money!. All of this is to say that when you “simply” move your fingers along guitar fretboard, you are changing the distances. Intervals can definitely get more complex than this so I think this will suffice for today!
The Distance Is Closed – You Are Now Interval Intelligent!
Knowing what a musical interval is may not seem that important right now, however, the more you learn about music the more you will see intervals popping up. Understanding intervals also make it easier to spot patterns which can really help you learn a lot faster than without them.
Please feel free to leave your thoughts, opinions or topics below.
I will be seeing you in the next post, Farewell Friend!