Keys are the foundation of music. They provide a framework for songwriting and help define each key's scale or modes so that musicians can create more complex pieces with multiple notes at once, as well as know when to use them strategically during performances.
Keys are divided into 7 major and 5 minor keys, making a total of 12 different keys. Every piece of music is played in one key or another—there's no such thing as "no key" or "it doesn't matter what key I play this piece in."
The term "key" isn't interchangeable with the term "scale," so don't get them confused. The scale of a song refers to the specific notes used and played repeatedly throughout it—kind of like an individual recipe for building a chord: mix equal parts F and A, add Bb and G#, etc.—while the key is more about how your choice of scales relates to other songs you know. Since there are many different types of scales that come from each key, musicians tend to be more concerned with keys than scales. Just remember that a song is in a specific key while a scale is a mix between many different keys.
What's In A Name?
Keys are named after the first note in the major scale they consist of, also known as the tonic (T). Each letter of the alphabet corresponds to a specific note—A, B, C, D, etc.—and notes can be referred to by either their name or the letter that represents them on sheet music; for example: if you see an E on your paper then it means to play an E. But since there aren't sharps and flats in every single key (F# and Gb aren't used very often), no one has to tell you that your E is actually F, Eb, or Bb.
The Seven Major Keys:
There are seven major keys, each starting on a different note. Since they're the most common keys in music, let's take a look at their scales to understand how they work.
The Major Scale:
When building a song in any major key, musicians use the notes of the major scale associated with it. These 7 notes are known as natural notes because they're found within all 12 keys and play no tricks on your ears. They are represented by the letters A to G—A being the first note, B is the second, etc.—with each letter representing a specific interval between itself and its predecessor (for example an A is 7 half steps away from a B). Visually speaking, intervals can be thought of like rungs on a ladder or slices in a pie; if you start at one note then jump up two you get another note that's two steps higher than the first.
The major scale is made up of two separate tetrachords (sets of four notes). These are split with a whole step (two frets on the guitar, one fret on most other instruments) in between them—the same way that steps are split when walking with someone else—before closing back into the beginning note or tonic.
Major Pentatonic Scale:
Now that we have our Ionian mode down let's take a look at the pentat scale. As opposed to using all of the notes on a major scale, musicians tend to use only the first five of them. This is what we call a pentatonic scale and it's very common in Blues & Rock music. Since there are 12 keys but only 5 elements (the numbers 1 through 5), certain notes get left out depending on which key you're playing in; these omitted notes are referred to as "accidentals" because they don't fit with the general pattern of things. But don't worry about memorizing that just yet!
Other Major Scales:
Now that we mentioned accidentals let's take a look at the rest of the major scales: harmonic major, melodic minor, and natural minor. Harmonic major is not too common and you won't see it used very often, if at all. Melodic minor is usually played ascending while the natural minor is more commonly played descending; though both can be inverted (played in the opposite direction). Inversions will be explained further down the page but for now, let's focus on what makes these scales different from major.
The harmonic major scale has a raised 4th note while melodic minor has a lower 7th note. The natural minor scale rises in 3rds while the other two fall in 3rds. As far as their pentatonic counterparts go, they're just a little bit different: harmonic major has a lowered 5th note while melodic minor sits right on top of its root note. Natural minor contains no chromatic notes (accidentals) while both major scales do.
Now let's take a look at the minor scale since it contains accidentals. Minor keys start on their own special note known as the tonic and work in much the same way that major does; meaning that they follow a specific pattern or sequence of intervals before coming back to where they started—and maybe inverted along the way if you're feeling adventurous.
Unlike in major, accidentals play a big role in minor keys since they're used to create tension that the ear demands be resolved. This means that it's almost always best to play each note as it appears on the paper rather than adding in extra chromatic notes (unless you want to experiment or are looking for a more avant-garde sound).
This is why musicians often name their scales "natural" with an uppercase N, which stands for normal. Relative keys are also common but we won't get into those here because they work very similarly to major and minor modes. The only real difference is that they're based on different starting points—meaning you can use them interchangeably if you really wanted to!
There are so many more scales than just major, minor, and pentatonic! You can learn about some of them right here. However, it's probably best not to try memorizing every single one of these scales unless you're already an advanced player because there are way too many options out there for any guitarist to cover them all in-depth. Just become familiar with the most common ones (major, minor, blues) and then pick which ones sound interesting or that you want to use on your next recording project!
Now let's take a look at modes; they're really cool but also very confusing without having spent years practicing as most professionals have! The thing is, you don't need to know about all of the different modes out there unless you're trying to become a professional musician. For now, we'll stick with Ionian and its other 5 brethren: Dorian, Phrygian, Lydian, Mixolydian, and Aeolian (also known as a natural minor).
The first thing that separates major and minor keys apart is that each has its own unique starting note—and this is where modes come into play. Each mode uses a distinct pattern of intervals to create the sound of their scales rather than using the same old 1-2-3-4-5-6-7 sequence like we've been doing so far. There isn't an easy way to explain why each one sounds the way it does or how its intervals work but you'll get a better idea by listening to them and then trying to play them yourself.
Just remember that since modes can be really hard on your ears if played incorrectly, we don't recommend using any of them until you feel very comfortable with major and minor scales and can play them smoothly and cleanly at high speeds. By doing so, you're essentially making sure there is no room for error before adding in another layer of complication!
When modes do come into use, however, they offer musicians an incredible amount of freedom when improvising because they allow each musician to play whatever kind of music they want without having to change keys (the key signature) like we've been doing so far.
Experimenting with Keys
Learning the guitar is a great way to improve your songwriting skills. Not only will it help you learn new techniques and improve what already exists, but learning chords will give musicians more ideas for their rhythm parts as well as lead pieces!
The chord progression is usually the first step to any song. If you don't have an idea for what chords to use or if you feel stuck in a rut, try thinking of your favorite songs and learning how they work! After all, musicians spend countless hours writing chord progressions so it's only natural that we take advantage of all that inspiration by getting started ourselves!
But let's not get ahead of ourselves here—first things first, you need to know the different keys out there before trying anything else! The good news is that once you learn them, scales will become much easier because this essentially means that instead of memorizing 12 different patterns (major + minor), you'll be able to create billions upon billions of different melodies with just 2 modes per key.
To put it in perspective, that means there would be 64 modes in major and minor keys which is a huge improvement from learning how to play a different scale for every single key! Trust us when we say it's definitely worth the effort since you'll have an infinite number of options when creating music on your guitar.
Although the guitar only has 6 strings, these 4 notes per string can create an incredible amount of possibilities. However, almost all chord progressions use just 2 or 3 chords so if this is your first time coming across these terms, understand that they're referring to major and minor triads (3-note chords).
You take the time to memorize scale positions to increase your speed.
To make this easier, you can think of a key as having only one starting note rather than being completely random. This will help you out tremendously when playing songs by artists who switch keys often during their performances! At first, though, it's best to use the same key for every piece that you learn. That way you can focus on just one scale and really get a feel for how it sounds without being distracted by too many other things at once.
Using guitar scales as a foundation for improvisation is an incredibly fun thing to do but don't forget that there are so many more techniques guitarists should know before doing something as advanced as this! In fact, scales aren't even necessary to play guitar—if you don't want to rely on them, there are still so many different ways musicians can create music without using scales! However, once you're familiar with them, they'll be your best friend when it comes to jamming out to your favorite songs or even just improvising something completely new.
Although this guide is designed for beginners, the more advanced players out there might have some trouble finding material that challenges them and their playing abilities. Just remember that challenging yourself is one of the best ways to get better and we encourage everyone —even experts—to learn something new every day! After all, we're not perfect and it's important to keep learning in order to grow as a musician (and a). Plus, learning stuff on your own can be just as fun as jamming with a group of friends!
So what have we learned? We've talked about the chromatic scale, major keys and scales, intervals, intervals in a tab, relative keys, accidentals, natural minor vs. harmonic minor, modes (Ionian mode explained), and guitar modes explained. If you want to learn more then here is a list of resources that can help you continue your journey! Good luck on your musical path!