i can see the confusion with chords. It depends in which context.

If you are playing a major scale, there are 7 different chords to learn, numbered 1 to 7, the most common played by guitarists is chords 1, 4 & 5. If you know those 3 chords in every major scale, you can strum along to any song in those scales.

From a different point of view, if you are a piano player. You can take the same chord and play it as 3 notes at once, or 4 notes at once, or 5 notes at once (need very big hand).

As a sax player, when you play a chord, you can only play 1 note at a time. I think When JF is saying chords 4 & 5 he is refering to the number of notes played in the chord.

I had a quick glance through the killer blues book, when he describes chords he names each note in the chord by the number of each note in the scale eg 1 3 5 say for c e g in a major c scale.

My sax teacher has got me singing these numbers in the correct pitch in various intervals so i can recognize the different intervals in a scale by ear. So if he says sing 1 2 3 1 etc.. when it comes to improvising later on, i can hear in my mind the different number patterns in my head & just pull them out on the sax when it comes to soloing/improvisation etc
The other side of it is when i listen to a solo, i should be able to recognise instantly which numbered notes are played

you must know all major scales and their chords, this is the key! When we say the numbers we are referring to the chords of the key (scale) the song is in.
when we say the 1 4 5 chords in the key of C major it means C F G
when we say 1 4 5 in E major it means E A B
all scales have 7 inherent chords that go up diatonically with the notes of the scale:
I’ll use C as an example: CM,dm,em,FM,GM,am,bd
3 major chords, 3 minor chords and 1 diminished chord (capital letters mean Major, small case means minor and diminished)
as you can see the 1 4 5 are major chords, the 2 3 6 are minor chords and the 7 is a diminished chord

all this chord related stuff is the most important basic music theory and is the basis of the course I wrote on how to improvise using only the notes of the major scale:
https://howtoplaysaxophone.org/major-scale-improvisation-course

Hey Jeffrey, one of the things I learned from Johnny being in KIller Blues myself is that it’s also much, much easier to transpose something from scale to another scale when we refer to this numbering system that Johnny refers to all the time and in music it’s a universal way of communicating with everyone, provided we know our scales and that’s why he teaches it. As an example, if Johnny says we’re improvising in the Key of C Major and Johnny refers to the 1-2-3 5 and 6/Pentatonic Scale, we know that he’s talking about C,D,E G and A. So, take that same number system and we can instantly transpose it to any other major scale. In G Major it would be G,A,B, D and E. In D Major it would be D,E,F#, A and B. Same thing goes for chords–when Johnny talks about 1-3-5 that outlines a chord in a scale, you can take that numbering system and quickly know which notes he’s talking about to play in any of the Major Scales–in C Major it would be C,E,G; in D Major it would be D,F#,A; in G Major it would be G,B,D, and so on. If we know of Major Scales inside-and-out, we can refer to that same numbering system when transposing songs to another key. If we see a song that is played say in F Major and you see something along the lines of, say in one measure, 2 half notes in a row played as C, and in the next measure there’s 2 quarter notes-one quarter note is Bb and the other is D–take a good look at those notes in that Major Scale of F Major: C in F Major is the 5th note of the F Major Scale, Bb is the 4th note of the F Major Scale and D is the D is the 6th note of the F Major Scale (we sometimes here these referred to as ‘degrees’ of the scale, the 5th note being the fifth degree, the 4th note being the 4th degree of the scale, etc). If you know your Major Scales inside-and-out you can very quickly transpose that song to other scales because of knowing the numbering system that Johnny refers to all the time. If you wanted to play that same musical phrase and transpose it to say C Major, it would be transposed as 2 half notes played as G, the first quarter note played as F and the 2nd quarter note played as A–how do we know this? Remember that in F Major C was the 5th note of the F Major Scale, Bb was the 4th note and D was the 6th note. Now look at any single Major scale that comes to your mind–which note on that scale is the 5th note/degree, the 4 note/degree and the 6th note/degree? Those are the notes we would play. That’s why it’s REALLY important to know our Major Scales really well when Improvising/transposing, as well as knowing our minor scales–we can never get too good at knowing our Major Scales. Same thing goes for the different kinds of chords we use in Saxophone playing like Major/minor chords, Dominant Chords, etc.. Johnny’s new Major Scale course takes these things were talking about 1-2 steps further (maybe even 3 steps) using modes of the Major Scales to Improvise with, so it’s really important to know your Major Scales absolutely inside and out if we get into that Major Scale course. I think I’mg going to reach my goal of starting Johnny’s new Improvisation course by the Spring!!! 🙂 Very happy–I’ve been working on the things in Killer Blues for a year now in October…has it been that long already?!? I don’t know, but I know the stuff in Killer Blues is pretty much part of my own “vocabulary” now and I can use it pretty freely in my own playing, so those things are indications to me that I’m just about ready to move on to his new course….almost anyway but not QUITE ready just yet…almost! 🙂 Thank You, Thank You, Thank You Johnny 🙂 The Blues Improvisation is GOOD stuff and it won’t get old for me anytime soon at all 🙂

The way you taught me to think in Killer Blues of the degrees of the scale/chords in terms of numbering system (if that’s what it’s called) makes everything so much simpler and it’s all really straight-forward stuff once we understand the music theory behind it. In starting to work with the guys on the Blues Society, everyone communicates using the numbers/degrees of the scale all the time…otherwise it would get pretty complicated LOL This is just one example of how your ebook helped me to start playing with others…as long as I’m in tune. I had to downsize 1/2 size of the reed on my Alto and it fixed the problem. I was perplexed after Careless Whisper because my tuner was showing I was in tune, so I didn’t know what to think. I started paying extra, extra close attention and noticed something that I hadn’t noticed before…there was a very, very small/faint “hissing” sound coming out of the side of the MP; it was very, very faint but it was there so I started doing some research online and found that this happens when we’re using a reed that is too thick/big/stiff and the reed isn’t vibrating like it should, even with the high-quality ligature/MP that I have…without the right reed it was useless. Other than that, I don’t think there was anything else wrong with my playing, was there? I’m sure I got the timing and everything right on the song. I’ll upload it again ASAP, we’re moving into our new house now! 🙂 Your autographed pic is going up on our wall 🙂

LOL That’s hilarious JB–yes, the mic NEEDS replacing; in fact I just did a private video for a friend using it and we both noticed some, “midi/robotic” type of resonance/feedback or something that was recorded and transmitted in my voice and I noticed it too, very weird sounding to say the least. It doesn’t have to be an expensive/elaborate mic either. Oh well, it served it’s purpose.