Morning Gordon,
Tbh, Iām not sure thereās much in the lessons that is not easily accessible elsewhere on the course or the web. I was sceptical that this was going to simply be a way of āinteracting with the communityā but regurgitating content we already have. In a way it is, but simply by joining in, means you have to focus on it and different areas are brought together giving it context.
Youād have no problem ācatching upā.
The simple answer to your value question is: sign up for a month and see if you like it. You can scan through the whole course and see whatās in it and how long itās worth keeping it for.
I signed up years ago and havenāt touched it for ages, but left my subscription going as itās one way of supporting J. 
Hi Stuart, you can have any number of bars you want in your chord progressions. My intent was not to say you had to have any particular number of bars in each section, just how many were in mine: 8, in both the verse progression and the chorus projection.
I reviewed the video again and Justin does talk about the number of bars in a couple of places, essentially suggesting but not mandating the number of bars in our chord progressions.
At ~ 12:22, question re difference between chord progression and chord family. (Note: the following is not verbatim from the video.), Justin answers that a chord progression is a sequence of chords that are used to construct a song usually. Theyāre very commonly 4 or 8 bars long, sometimes 12 or 16, sometimes an odder number. The majority of the time itās 4 bars or 8 bars.
At 1:06:31 Justin says ālike I said it could be a 4 bar chord progression, or it could be an 8 bar chord progression. If you want to keep it simple just stick with a 4 bar oneā.
At 1:07:48 Justin makes a reference to āthe 4 barsā
Justin does talk about the number of bars, but as I noted above he doesnāt mandate a specific requirement.
Re recording your chord progression, a couple others had done so, although most simply posted their progressions. I enjoyed listening to the posts of people playing their chord progressions, so I decided to record mine as well.
Mari
Thought Iād share a progression I knocked up a few weeks back to practice one of the fingerstyle patterns Iāve been working on. Iād not really analysed it before today but just laid down a rather melancholy muse, with lots of minor chords.
I now see it is modally A Aeolian (mm I think 
). So chord wise the choice would be : Am Bdim C Dm Em F G.
I donāt recall the remit being limited to the Major scale, so hope Iāve not overstepped the mark going down the Mode 
The progression can be broken down into 2 verses and a chorus.
V1 Am Am Em Em (i i V V) x 2
V2 Am C Em Em (i III V V) x 2
C. G Dm Am Am (VII iv i i) x 2
Have yet to have a clean run at recording this piece, so for now Iāve exported the GuitarPro audio (Key and Drum midi added to Reaper project) Gtr is Clean Electric but I am currently playing this on acoustic.
Hey there, I really enjoyed the live class and tried to do my homework - even inserted some secondary dominants 
Key G major
Verse:
|G - - B7|Em - - E7|Am - - A7 | D - - -|
Chorus:
|D7 - - -|G - G7 - |C - - D7|G - - -|
Now I have to get back to practising and look forward to the next live class 
Hehe, I donāt even have to listen or play that to know that sounds ace with all those minors
I donāt recall him saying anything about having to be major (although that was what he was talking about)
Just dropped a recording in the-madmans-learning-log in reference to my post above, if anyone is interested. 
No problem. I was responding to the text from here https://www.justinguitar.com/guitar-lessons/music-theory-live-class-i-chords-in-keys-pmtlc-001 which is 
āI have a challenge for you to complete before our next session! If you follow along with my challenges and stick with these Live Classes, weāll build up something cool. The Challenge for Live Class I is to write two chord progressionsā,
Happy to listen to them but I wont be
That is great, much cleaner chords than I can play. All sounded very musical and fitted together well.
Finally got round for a listen Mari and really enjoyed those progressions. Some great chord choices, sounded real sweet. And the Gm fitted like a glove
Wow! I just listened to your recordings and they all sound very sweet!
@TheMadman_tobyjenner Iām a minor chordsā fan as well, why do they say theyāre sad? I thought that playing with the backing track made your fingerstyle really richer, I enjoyed that! 
@Mari63 you played some very sweet chords there! I liked the strumming too 
@TheCluelessLuthier your chords were very sweet too to my ear and loved the fingerpicking patterns
I have my progressions ready and only need to find sometime to recordā¦maybe tomorrowā¦I read your discussion about the number of bars and Iām afraid my verses are to short (only 4 bars) But Iām leaving it the way it is at the moment, itās just exploring and experimenting funā¦no more than something to learn from.
Thank you Silvia, you canāt beat a bit of mean and moody.
I watched the video after the live session and really enjoyed it. Iām taking the Music Theory course and found that the live class reinforced and clarified some things with which I was already familiar. And there were enough new concepts to pique my interest. Some discussion was over my head but that was OK; I expected that. For the first attempt I thought this was outstanding and I look forward to more!
Thatās not too short at all, Silvia. Justin referred to progressions as being commonly 4 bars or 8 bars. They can be any length you want really, but I interpret Justinās comments as saying that 4 bars is fine.
Mari
@SILVIA Sylvia, to echo what @Mari63 said, I thought I heard Justin specify two four- or eight-bar progressions, one feeling like a verse and one like a chorus if you can do that. Iām in Grade 2 guitar/Grade 3 PMT (Iāve read Grade 4 but havenāt done the exercises), so there wonāt be any fancy stuff coming from me at this point!
@Uninvitedguest i quite liked your progression, and I thought the similarity between the opening bars of both our progressions was kind of cool!
Thanks Toby. Now if I could only figure out why it worked, or if itās just one of those things that work even though it maybe shouldnāt!
The Gm chord has the note Bb, which is not in the key of A major and sounds pretty rough over an A major chord.
If I let my ears guide me, then I perceive a different tonal center when you play the Dadd9 - Gm - D - A - E part. The E major chord at the end almost sounds out of key to my ears. As if you quickly modulated to a different key and then returned to the key of A major.
Another way to think of it, is that we borrow the Gm chord from a different key where it naturally occurs:
- major keys: Bb major, Eb major and F major
- minor keys: G minor (natural/harmonic/melodic), C minor (natural), D minor (natural/harmonic) and F minor (melodic)
The Gm chord is also found in the A phrygian mode.
Which one is it? I guess you can look at it however you want, but it doesnāt matter. It sounds lovely.
A video of the chord progression:
Thatās a lot of analysis @Jeff ! It kind of lands on āif it sounds good it is goodā, and thatās kind of where Iāve landed too, with no specific explanation 
Em / D (or Bm7) / C / B7 (related or āstolenā from the Andalusian Cadence)