Music theory question about Keys

[Troyboi]

Hello, This is my first post and I have just started learning to play guitar. I'm also trying to learn all about music theory which I'm slowly getting the gist of things but must admit I am struggling with some of the concepts like modes.

Anyway I was reading about Keys today such as the key of C. Am I correct in saying that if a song is in the key of C it just means that all the chords used in that song only use the notes CDEFGABC?

[Kyle76]

That's correct, and that key has no sharp or flat notes. I think all other keys include at least one sharp or flat.

[Bikewer]

If you make a "harmonized scale" in the key of C, using triads built up only out of the notes in the scale, you can get the standard chords used in that key.

It's the building block for chord progressions.

[Troyboi]

Aha. Ok then, well at least I understand that then, thanks for the replies.

So what exactly is a mode then? I know there are different modes like Ionian and myxolodian etc but what are they exactly? I don't quite get what a mode actually is.

[fatt-dad]

The, "Key of C" is not enough! The, "Key of C-major" will then inform the notes.

If you are just learning, just play!

Babies learn to make noise, learn to make words, learn to form sentences and learn to actually communicate, before they get to school. Then after a few years of school, we introduce subject, verb and noun.

Just get notes under your fingers!

f-d

[stanron]

Originally Posted by Troyboi

Am I correct in saying that if a song is in the key of C it just means that all the chords used in that song only use the notes CDEFGABC?

Hi.

Mostly but not neccessarily. There can be exceptions. Music theory is more 'observed common practice' rather than 'mandatory requirements'. Rules are there to be broken.

The scale of C contains seven notes.

C, D, E, F, G, A and B

in different combinations these notes can make the chords

C, Dm, Em, F, G, Am and B dim

If you decide to change the minor chords to major chords, and there are songs where this happens, you use notes that aren't in the scale.

If you are new to playing guitar there is a lot to be said for just learning songs and leaving theory until later.

By then you will have first hand experience of what theory is about. I would suggest you start theory with trying to read notation. When you can read simple notation then try learning more theory.

[Riverwolf]

Originally Posted by stanron

If you are new to playing guitar there is a lot to be said for just learning songs and leaving theory until later.

(like he said )

Welcome to the forum!

4.5 years later, I know very little theory but have a continuing list of progressively harder to play songs.

Some simple transposing of chords and runs from one key to another has helped though.

[charles Tauber]

In theory, yes. In practice, maybe.

One of the ways of making music more interesting is to change keys during a piece of music. In that case, the chords might contain notes that don't belong to the key from which you are leaving: they belong to the key to which you are changing.

Another way of making music more interesting is to add notes to chords that don't belong to that key. It can add harmonic interest - usually tension.

In the simplest terms, a mode is a sequence of 8 notes (7 unique and the octave of the starting note repeated) that follow a specific pattern. In Western music, a scale has 8 notes. Label each note with a Roman numeral. In the key of C, C, the starting note is I; D is II, E is III and so on.

In any key, playing in succession only the notes of that key, I can be called the Ionian mode. II can be called Dorian mode. III can be called Phyrigian, and so on.

For example, in the key of C, the Ionian mode is C, D, E, F, G, A, B, C. Dorian is D, E, F, G, A, B, C, D. Phyrigian is E, F, G, A, B, C, D, E.

What remains the same in each mode is the distance between each of the successive notes in that mode: it is what defines that mode. For example, the Ionian mode is defined by the sequence of notes that are a tone apart, a tone apart, a semi-tone apart, a tone apart, a tone apart, a tone apart, a semi-tone apart: C to D is a tone apart, D to E is a tone apart, E to F is a semi-tone apart and so on. This is also the sequence that defines the major scale (that can be called the Ionian mode.) If this sequence is adhered to, regardless of the starting note, the sequence will form a major scale: that is what defines the major scale as the major scale.

https://en.wikipedia.org/wiki/Mode_(music)#Modern

[rick-slo]

Originally Posted by Troyboi

Anyway I was reading about Keys today such as the key of C. Am I correct in saying that if a song is in the key of C it just means that all the chords used in that song only use the notes CDEFGABC?

Incorrect. Any note could be used. Probably the best example is seventh chords where in C7 the Bb note is used. Or you might substitute a F minor for a F major chord where a G# is used. Etc.

[charles Tauber]

Originally Posted by rick-slo

Or you might substitute a F minor for a F major chord where a G# is used. Etc.

If we are talking theory, an F minor triad has the notes F, Ab and C. There is no G# in an F minor chord. Ab and G# have the same pitch, but have different relationships to F. In theory, at least, the relationships matter.

The Bb does not belong to the key of C major. If one understands that the Bb makes the C chord, amongst other possible options, a dominant seventh chord (V7) in the key of F, it helps one to understand what chords might follow the C7 chord and how the listener would like to hear the notes of the C7 chord move (resolve).

The Bb added to the C chord can also be used simply for embellishment without regard for harmonic implication, as is often the case. Flat thirds, flat fifths, augmented fifths and flat sevenths are often used as chord embellishment to give added "character" to music.

[rick-slo]

Originally Posted by charles Tauber

If we are talking theory, an F minor triad has the notes F, Ab and C. There is no G# in an F minor chord. Ab and G# have the same pitch, but have different relationships to F. In theory, at least, the relationships matter.

The Bb does not belong to the key of C major. If one understands that the Bb makes the C chord, amongst other possible options, a dominant seventh chord (V7) in the key of F, it helps one to understand what chords might follow the C7 chord and how the listener would like to hear the notes of the C7 chord move (resolve).

The Bb added to the C chord can also be used simply for embellishment without regard for harmonic implication, as is often the case. Flat thirds, flat fifths, augmented fifths and flat sevenths are often used as chord embellishment to give added "character" to music.

I'm fine with the enharmonic choices and Ab would be more correct notation (substitution of chord from the key of F minor versus simply an altered chord).
As to the rest, it is an example of why I dislike music theory obscuration piled on a basic question. Save if for another time IMO.

[charles Tauber]

Originally Posted by rick-slo

I'm fine with the enharmonic choices and Ab would be more correct notation (substitution of chord from the key of F minor versus simply an altered chord).

The theory is pretty clear. It isn't a question of "more" correct. There is no G# in an F minor triad.

As to the rest, it is an example of why I dislike music theory obscuration piled on a basic question. Save if for another time IMO.

Interesting.

Music theory, by those who study it and understand it, can provide insight into music. It's curious that you find that it creates "obscuration".

If you hadn't "piled on" the basic question with a half-baked discussion of altered (non-diatonic) chord tones, I'd have no reason to mention them.

[rick-slo]

Originally Posted by charles Tauber

The theory is pretty clear. It isn't a question of "more" correct. There is no G# in an A minor triad.



Interesting.

Music theory, by those who study it and understand it, can provide insight into music. It's curious that you find that it creates "obscuration".

If you hadn't "piled on" the basic question with a half-baked discussion of altered (non-diatonic) chord tones, I'd have no reason to mention them.

I'll let this pass. Happy father's day.

[JonPR]

Originally Posted by Troyboi

Aha. Ok then, well at least I understand that then, thanks for the replies.

So what exactly is a mode then? I know there are different modes like Ionian and myxolodian etc but what are they exactly? I don't quite get what a mode actually is.

There are two ways of thinking about them: relative and parallel.

Relative modes use the same 7 notes, but a different note is treated as the tonal centre, or keynote. This is the sense in which people say "the C major scale has 7 modes". These would be as follows:
C ionian
D dorian
E phrygian
F lydian
G mixolydian
A aeolian
B locrian
While this angle is often used in teaching to introduce modes, it's the least useful and most confusing when it comes to musical application.

Parallel modes are modes which all have the same root note or tonal centre, but different scale formulas on top. So the parallel modes on C would be:
C ionian (C D E F G A B C)
C dorian (C D Eb F G A Bb C)
C phrygian (C Db Eb F G Ab Bb C)
C lydian (C D E F# G A B C)
C mixolydian (C D E F G A Bb C)
C aeolian (C D Eb F G Ab Bb C)
C locrian (C Db Eb F Gb Ab Bb C)
This angle is much more useful when understanding how modes are used in music. (Each of those modes is the same notes as a particular major scale, but the difference is that the keynote is C in each case.)

Because so much of the music we're used to hearing is based on major and minor keys, we tend to hear modes as variations on the nearest parallel major or minor key, and it helps to list them in order from "brightest" to "darkest";
C lydian = C major with #4
C ionian = C major
C mixolydian = C major with b7
C dorian = C minor with major 6th
C aeolian = C (natural) minor
C phrygian = C minor with b2
C locrian = C minor with b5 and b2

Another common difference between music written in keys and music written in modes is that key-based music often (though not always) uses more chords, and faster chord changes. Modal music tends to have fewer chords, and one chord (or a pair of alternating chords) commonly lasts for a long time.

In jazz, there is even more difference: "modal jazz" tends to use chords built in 4ths, which sound like various types of sus chord; and when chords change, they change to chords using a different mode or scale. This is because modal jazz was deliberately designed to break with the past system of key-based music (centered around lots of chords mostly derived from the same scale).

In rock, rules are much less strict (because who cares, frankly!), and the most common practice is "mode mixture", which means the use of chords from both the parallel major and minor keys. So you can have a song "In the key of E major", using the usual E, A, B7, C#m (etc) chords (harmonized from the E major scale), but it might also use chords like D, G, C or Am, which work because they all come from the key of E minor. So you could say the tune was "in the key of E", understanding that the major/minor distinction is blurred. However those chords are used, the key centre will always sound like E.
The whole concept of keys and modes alike depends on being able to hear one note or chord as the tonal centre. We identify a key (or mode) by listening for a tonal centre (point of stability) not by looking at a piece of music.
Having said that, there's a fair amount of music around now (particularly in R&B and hip-hop) where it's hard to identify a key; the chords may well all come from the same scale, but - because of the practice of sequencing repeating chord loops - none of them really "sounds like home", the way it does in older forms of pop and rock.

[RustyAxe]

Originally Posted by Troyboi

Anyway I was reading about Keys today such as the key of C. Am I correct in saying that if a song is in the key of C it just means that all the chords used in that song only use the notes CDEFGABC?

No. I"m gonna say something that'll get me a lot flak. If you're new to guitar and don't already know music you're trying to put the cart before the horse. Just learn a few simple chords, learn some songs using the chords, and as you play more songs you'll begin to see "patterns" that recur. You might get interested to know why these patterns work. That's the time to begin thinking about theory. For a new guitar player to even THINK about modes, various scales and such (as some here have tried to explain), is silly ... it's just information overload. While trying to be helpful, some people post things that original poster cannot grasp, and the thread turns into a debate between pedants.

One need not know nor understand the engineering that goes into the car they drive, and can very happy just driving it. But if one cares to go further, one can.