We start off our historical overview at the beginning of the 20th century. When we talk about early jazz period in general, and the contributions of various artists in particular to the development of jazz, there is one name in particular that deserves our deepest respect and gratitude, the great trumpeter, Louis Armstrong. When you listen to Armstrong's rendition of the blues. Take for instance, West End Blues from 1928. You can hear in his playing a tremendous amount of expressiveness and palpable emotions. And even though Armstrong plays on the one chorus and is very economical in his approach to improvisation. That single chorus tells a complete story. Just as the spoken words would. Also, when you listen to other early jazz artists and composers, such as W.C. Handy, who is the considered the father of the blues. And his compositions, Saint Louis Blues, or Memphis Blues. Or Louis Armstrong mentor, King Oliver, or Dippermouth Blues or Jelly Roll Morton, New Orleans Blues, or Sidney Bechet on Blue Horizon. In all of these compositions, and performances you can hear palpable emotions and expressiveness conveyed by the individual players. On the slide, on the screen, you can see the realization of the progression with fully realized chords. But I'm going to embellish that early jazz blues progression with some idiomatic rhythmic and melodic devices. Nothing too crazy. Just simple rhythmic embellishment. So listen to that progression and it comes from the early jazz period. Then we'll discuss the content. [MUSIC] So when you listen to the chord progressions, notice that all the chords are basically simple four part chords, seventh chords, which the exception of few triads here and there. When you listen to the first measure. [MUSIC] Even though a single chord occupies the first measure, early jazz performers like to utilize chordal inversions. The second chord, appears in the second inversion. Another idiomatic feature of the early jazz blues, early jazz harmony, is the presence of the minor four chord. [MUSIC] Minor four, and the use of the many seventh chords [MUSIC] in their passing capacities. For the most part, the harmony of early jazz was mostly diatonic with few notable exceptions and you can hear these exceptions at the end of the four in measure 12. When I go from [MUSIC] been ultimate chord g flat seven is build on flat six scale degree. Which is very characteristic chromatic color in early jazz music. So the use of four-part chords and chordal inversions with few notable harmonic and chromatic alterations, especially chords on flat six scale degree, and the use of potent blues content. For instance, the last two measures in here. [MUSIC] That's the note that gives us expressive potential. And power of the blues. Diminished seventh chords, diminished passing chords. [MUSIC] Now, when you compare the early jazz blues with the swing blues you'll immediately recognize some notable differences, listen to the adverse. [MUSIC] So the most important difference between early jazz blues and the swing blues is faster harmonic rhythm, larger chord structures, the use of walking tens in the left hand, and the far extended role of the diminished seventh chords. So check out the first measure. You have [MUSIC], the very first chord extends the basic four part structure into the five part chord with the added ninth. And then going to the second measure, we hear the use of dominant seventh chords. Chordal inversions are still part of the style, but in general, faster harmonic rhythm and far greater use of dominant seventh chords are the main characteristics of the swing period. And you can hear the use of these devices in the playing of Teddy Wilson, particularly his version of Blues For Daryl. And Earl Hines on the iconic West End Blues from 1928 which I had already mentioned, and his Blues in Thirds. The next historical period, bebop, ushered in a number of revolutionary changes to the chord progression of the blues as well as do improvisation. Listen to a more progressive blues version from that period. You will notice that the harmonies are far more chromatic. And the rate of harmonic rhythm is far greater than an earlier period. Also the use of chromatic progressions, especially chromatic 251s will dominate that style. If you're overwhelmed with my jargon, chromatic 251 substitutions and other things that I use, don't worry. We'll come back to these concepts, and we'll talk about it. But for now I just want to give you an overview of how the simple blues progression becomes far more progressive and far more challenging to improvise. So listen to the version of A typical bebop blues. [MUSIC] When you compare these versions, the swing blues, [MUSIC] Immediately we're drawn to some notable differences, right. The next period. Post-bop. Is significantly different. One thing that didn't change in the blues is the presence of the structural chords. And once we discuss the role of harmonies in the form of the blues. These concepts will be clearer. In the 50s, especially in the late 50s, the blues might have sounded like this. [MUSIC] It's completely different from your earlier [MUSIC] Or even the bebop blues. And to make things even more intricate, in the 50s the fascination with harmonies, with different harmonic chords seem to be one of the main things that occupied the works of different composers and artists. Listen to this version. [MUSIC] It's completely different from our earlier blues. As you can see, there is a lot of harmonic variety in the blues progressions. But one thing common for all the blues progression. Is the overall form and the distribution of structural chords. Before we move to the discussion of the form of the blues, let me just say that sometime we take for granted the fact that musical style changes constantly and with that change we also have to adopt our improvisational techniques. For instance, when we improvise on an early blues as opposed to post-bop blues, our improvisational strategies will be completely different and that's what we're going to study in this course.