The key of....

When someone says this will be in the key of C, or G, or whatever, how do I know where that is?  Do you have to memorize the entire fretboard?

You don't have to memorize the fretboard, but you should at least memorize all the notes on the 6th string

You can play everything from this string, either scales - minor or major or chords - minor or major using barre chords or power chords. That will cover a lot of songs or jams.

You should also learn the major pentatonic scale pattern and the minor from this string as well if you don't already know them. 

And the key means root. So key of C means the chords will be in the key of C - either major or minor and so will the scales - major or minor.

If you want to know what belongs to each and don't want to memorize the formulas, go to this link below.

Keys

Edit:

I am going to add a bit to this, not knowing how deep you want to go into this, but there are times when a "note" is not a "note". Example, you may be learning a song and a lick has the following notes: E E C# / D D C A.  You can find those notes anywhere on the fretboard, however, if you aren't playing the EE's on the 5th fret of the 2nd string, it won't sound correct to the song.

So when I am learning song parts I try to figure out where on the neck the parts are being played.

Thanks as usual to William for the great reply!

When a piece of music is in a key that means it is primarily using notes from that scale.

Example: "This song is in the key of C major".  Meaning:  the melody (riffs, licks, etc.) and chords in this song use notes from the C major scale.  That is what a key signature is.  Where is it?  Everywhere on the guitar you can play that scale.

If you've learned the song by learning the chords used, the chord progression and the strumming or picking rhythm, then you don't necessarily need to know anything about the key signature.  The key is already contained in the info you are using (the chords & progression).  Mentioning the key is more about conceptually identifying what is going on, but not necessary to know.

On the other hand, if you are jamming with people & are expected to improvise a melody (take a solo!), then you will need to know some scale patterns and how to make musical phrases with them.

In this case, you would need to know: the location of the note C on the guitar fretboard, the C major scale pattern, and how to make some music with the scale.

You don't have to know the entire fretboard.  But you are going to be limited to only using the area with which you are familiar.  If you only know the open C major scale position, that's fine.  Start with that!  And then work on learning more of the scale in a different fretboard location to expand your skill set.

You might find my tutorials on improvisation helpful.  The first one starts simple with the basics & includes a lesson on identifying the key signature.

https://www.guitartricks.com/collection/learning-to-improvise

Hope that helps!

Thank you very much...I need to get on my guitar to see if it makes sense to me!

Thank you William MG.  One more question, you mention learning the major and minor pentatonic scales, which I did learn them from Ander Mouresen's lessons, but not really what I can do with them.  Also, people started stated talking about the major and minor in different positions?  Now I'm wondering after all the time I've put in so far, am I getting anywhere?

I can go through the lessons, but after practicing consistently, every day, with a rare miss, I can't play anything, I can just follow the lessons?

DJ

I know you directed this at William, but I'd like to provide some direction.

You can only play the things that you've learned, worked on or that are in your current skill set.  That's all any of us can do.  

So, what do you want to be able to do?  You might want to make a list & prioritize your goals.

The fundamentals lessons are designed to help students build skills from zero.  After that you've got to apply those skills to the next step.  Pick a direction, then learn more skills and apply them to songs.  

Do you want to learn a specific song?  Start working on that song.  Look for songs at your skill level.  If you encounter skills in a song that you don't yet possess, then start working on building that skill.

You've mentioned the pentatonic boxes and major and minor scales in a few posts. You can use those scales in so many different ways and at so many different levels that it's difficult to answer without knowing the specific skill level, preferred style or goals of the individual asking the question.

It really depends on where you are and what you want to do.

You can do simple things with the pentatonic scale and basic major scales like this:

https://www.guitartricks.com/lesson/16008

And you can do things that a little more involved like from these tunes.

https://www.guitartricks.com/lesson/22545

https://www.guitartricks.com/lesson/19525

Or you do much more advanced things with the pentatonic scale like this:

https://www.guitartricks.com/tutorial/2458/

It's in the main riff and all over the solo.  But it's a more advanced skill set.

So, what do you want to do that you can't yet?

I would just like to add to what Christopher has down, and I know it's a lot of information coming your way. In his reply I think he hit the nail on the head - you have some training, you know some parts - but then what? You are only lacking a little self direction.

What helped me understand how the pieces of this musical puzzle fit together is when I challenged myself to write a song. I had some chords down, some scales, but the question was - and you are asking it - "why". Why did the song writer put those chords together and why were those notes used to play the solo parts, and to your question as to positions on the neck - why did Ace jump all the way down to the 20th fret to play a G note when there are much more comfortable positions on the neck to fret that G? Well in the case of Deuce, you just have to listen to the song - that closing solo is the climax of the song. It's all about effect and what an effect it has!

One more word on your question about what to do with the scales you have learned. I am very easy on myself. I learned that I really have no talent when it comes to writing music, I enjoy writing lyrics, but my music is always stale and boring. It is correct however, I always stay in key, but BB King could take 3 notes and make them sound like magic, I make them sound like notes.

So I tend to use a lot of the same licks when jamming with friends. Why reinvent the wheel? This weekend we have a jam, we are all old, we just have fun. We play some tunes, easy tunes,  talk about how it used to be and why our generation and its music was best and have some laughs.

Keep asking questions and enjoy the process of learning. 

Hey man,

so I was thinking about this:

"you mention learning the major and minor pentatonic scales, which I did learn them from Ander Mouresen's lessons, but not really what I can do with them.  Also, people started stated talking about the major and minor in different positions?  Now I'm wondering after all the time I've put in so far, am I getting anywhere?

I can go through the lessons, but after practicing consistently, every day, with a rare miss, I can't play anything, I can just follow the lessons?"

...whilst I was messing around with "Yngwie's Simple Shred lick" I just learned...

so I thought I'd share my perspective on this.

the vid itself is a question to Schlegal about what I'm doing music theory wise... by combining
the Yngwie lick (built of a particular scale)
+ that chord
+ that pull-off
+ that final note.

then after my question I thought... well that's just the thing:
you just gotta play with stuff... that's all the greats are doing

it's just that you get more and more of an idea what you are doing the more you do it and the more you intellectually learn

but all the intellectualizing in the world isn't going to help you actually understand 

you just gotta get IN the music... and feel around.

so anyways... here's the vid

Like William said you need to know the notes on the 6th string and I would say the 5th also. From there I start with the L and inverted L from the beginner courses. This gets you to the chords in the scale. I know that the only the 1, 4 & 5 chords are the same, meaning major or minor. So in C major the C, F & G are major. In C minor the C, F and G are minor. From there you just need to know the steps and that the 7 is diminished in Major and the 2 is in minor.