The numbers you see in extended chord names always refer back to the major scale, even when the chord is not major. So when you read that minor chords consist of 1-♭3-5, that ♭3 is the note one semitone lower than the 3 of a major third; ♯4 means the note one semitone higher than the major 4; a chord like Asus4♯5 means that the root is A, the 3 has been replaced by a 4 (sus) and the 5 has been raised.
They didn't make it easy for us, did they?!
We've only really just touched on the subject of chords in these last pages. It's a subject that will keep you busy for years to come and you will have still only scratched the surface. I've been at it since 1961 and everythime I pick up my guitar — which is often — I seem to stumble onto some new tidbit of knowledge when it comes to chords. As I have mentioned already, the more you know about chords, the more you know about scales and harmony, since chords encapsulate both of those topics. After playing for a while, you will begin to understand that chords are not just little clusters of notes arranged in familiar shapes, but that they are in fact arrays of notes that stretch from one end of the fretboard to the other, and that when you can see them as such, you're also looking at all the strongest melody notes for that moment in time. This will come come in very handy when you start delving into the art of improvisation or composing your own music. The grid of the fretboard becomes the graph paper against which you'll be plotting it all out.
But, don't let the enormity of the subject daunt you. The detail is endless, but the basic entities are few and easy to understand. It's a little like mixing oil paints: there are countless tones and shades but all come from just a few primary colors. I've been at it for so long that I just see one almighty chord that can be morphed into different flavors and moved up or down in pitch.
Some things to keep in mind
There are really only two main flavors: Major and minor. They can be played as three note chords called triads. Minor chords can be seen as major chords with a ♭3. That may not mean much to you at this stage, but soon enough (if you're serious about being a good player) you'll learn which tones are which and you'll be able to literally see the 3s on the fretboard in amongst the 1s and 5s. So a Major chord is 1-3-5, minor is 1-♭3-5. Guitars have six strings so you can use more than one of each, in any way you want. Knowing the actual names of these notes isn't nearly as important as being able to recognize which are which by their scale degree, their number.
The other two chords that can be played as triads are the augmented (1-3-♯5) and diminished (1-♭3-♭5) chords, and they're fairly uncommon. But, you can see how the min, aug and dim triads are in a sense variations of the major triad. That's why knowing all major chords is so important. If you know them, you can figure out all the rest.
There are two different kinds of 7th chords: Major 7th, which are triads with one more note added into the mix: the 7th note of the major scale. That extra note is usually added as the highest note in the chord, but can be thrown in anywhere, even as a bass note if that's what you want to hear.
The other kind of 7th uses the next note down in pitch from the major 7, the ♭7. These chords are also known as Dominant Sevenths and are very common in our kind of music. They have an unstable sound and often are used to lead from one stable chord to another.
Suspended chords have no 3. They are neither major nor minor. The 3 is replaced by either a 2 or a 4, which are the two scale notes either side of the 3.
Extended chords are the 9ths, 11ths and 13ths ... those 'bigger than 7' numbers. So they're 7th chords with notes added 'above' the 7. They're called 'Major 9th, 11th and 13th' if the major 7 is there; If it's the ♭7, they're just called 9th, 11th and 13th.
Remember that at the core of just about every chord you will encounter, there's either a major or minor triad and that if you get stuck momentarily trying to flesh out extensions, you can always just play the triad notes and be on safe ground.
Most important of all: Learn the CAGED shapes. If you know them, and know which tones are the 1s, the 3s and the 5s, the rest will come easy ... even if you don't believe it right now.