Matthieu spends the first section of the lesson going over some the intricacies of the note voicings of chords. Tonics, minor and major thirds, fifths and sevenths mostly. These voicings make up the backbone of jazzy II-V- I or standard I-IV-V chords of 90% of various "common" progressions. This is knowledge we need to know if we want to play music rather than a just a few simple chords.
He and others call it Jump Blues which Mr. Brandt tells us originated in the 1940's and 50's with big bands like Louis Jordan and that subsequent others such as T-Bone Walker, B.B. King, Freddie King, Clarence Gatemouth Brown, Robert Junior Lockwood and Charlie Christian. This is dance-able music. Duke Robillard, Rod Piazza and the Might Flyers, Ronnie Earl, Brian Setzer, and Little Charlie and the Nightcaps keep Jump Blues alive in the new Millennium. Louis Armstrong (Satch-Mo) is credited with pulling together the bits and pieces we call "Swing" and that provided fertile ground for Be-Bop, Jazz and so-called Western-Swing Guitar. Also Rockabilly as defined by the Reverend Horton Heat, The Chop Tops, The Meteors and Brian Setzer uses recognizable riffs, licks and horn stabs from big band orchestras.
He starts us off in section one playing 'back up' or rhythm guitar but what he really means is chord voice leading but before we can do that Matt shows us that we have to learn where our octave centers or tonic notes are. We have to learn the notes if we haven't already. Not all the notes exactly with 100% accuracy but well enough to finger the chord shapes/moves within a reasonable period. You pick a key. He uses C a lot which means no sharps or flats. Good! Very Good! C is your master key.
Learn that first ideally but its one of the hardest to learn at the open position. Better to learn it 'E shape' barred at the (C) 8th fret position and the associate 1-4-5 barre chords related to C or Learn it the C-A-G-E-D way with triad shapes.
Challenges are what make life interesting and overcoming them is what makes life meaningful. – Joshua J. Marine