On the screen, you can see the pitch structure of the Blues Scale. The expressiveness of the blues comes from the melodic inflections added to particular notes of that scale. The blues scale is a six note collection, where the blue notes on flat 3, flat 5, and flat 7. Here's the scale. [SOUND] So there is an inherent hierarchy among pitches of the blues scale, and certain tonal implications of the blue notes. For instance, flat 3 [SOUND] has a strong minor flavor and flat 7 [SOUND] implies the sound of the dominant 7th chord. Probably the most dissonant note from the blues scale is the one tritone away from the root, [SOUND] flat 5. And that note carries the most expressive potential. So when you listen to the sound of these blue notes, [SOUND] flat 3, flat 7, and flat 5. The flat 5's probably the most expressive of them all. But what is really special about the blue notes is that in spite of their strong tonal implications, these notes are not bound by any particular harmonic or melodic function. Which means that they can be added to just about any chord type regardless of their functionality, quality. So for instance, if I add these blue notes to the major type chords, it sounds like this. Here's my B flat major chord, in the left hand. [SOUND] And I will superimpose the blue notes in my right hand. Flat 3 [SOUND], flat 5 [SOUND] ,and flat 7 [SOUND]. So this note, the note change the quality of the chord, and the same thing goes for minor chords. [SOUND] So that the flat 3 and flat 7 have strong harmonic tendencies in tonal music is well established fact but not necessarily in the context of the blues. So in short, not only will the addition of the blue note to your solo add powerful melodic dimensions to your playing. But it will also enhance the expressive qualities of your improvisation without compromising the qualities of the underlying chords. Now, we're going to discuss the close cousin of the blues scale which I call the major blues scale or Lester Young scale and I will explain momentarily what these labels mean. So again, when you listen to the sound of the blue scale starting on B flat [SOUND], that scale, even though it's has that unmistakably minor feel to it. Basically on account of the minor 3rd. But when we start that same scale on the 2nd note, on flat 3, and continue it through the scale. [SOUND] You notice that the new scale has a major quality. So again, we rotate the pitch collection of the blues scale one note up, and we start our scale on flat 3 [SOUND], and continue it through a scale. [SOUND] So that's our major blues scale, D flat major blues scale. [SOUND] So when you listen to the sound of that scale, it has major quality [SOUND], right? So that scale still has the blue note, flat 3 [SOUND], but unlike the regular blues scale, it also contains major 3rd [SOUND], perfect 5th [SOUND], major 6th. So as such, major blue scale's a perfect candidate to be used over a variety of major chords as well as dominant chords. The reason the major blues scale is called Lester Young scale is because Lester Young in the 30s and 40s showed some amazing melodic creativity with that scale. When you listen to his solo on Lady Be Good or his take on Lester Leaps In, you will hear how much creative content can be generated from that simple melodic collection. In order to generate B flat major blues scale, our regular blues scale has to start on G. So here's our G blues scale [SOUND]. And now we are going to rotate that scale starting on the second note [SOUND], B flat, [SOUND]. Okay, [SOUND] so that's our B flat major blues scale which we can use in our improvisation. So just do keep in mind that these two blues scales, regular [SOUND] and major blues scale [SOUND] can be used interchangeably during your solo. I mentioned earlier that the major blues scale has similar pitch content to that of major pentatonic scale. So here's the structure of the pentatonic scale on B flat. As the name suggest, it has only five notes unlike blue scales which has six notes. So here's your B flat pentatonic scale. [SOUND] The main characteristic of the pentatonics is the absence of semi-tones, and the varied intervallic content. The absence of semi-tones makes that scale sound serene, and without particular tonal tendencies. In lecture five, we're going to return to the discussion of pentatonics and use them to generate various model voices.