 Okay, so now we've done a lot with roots and fifths and playing through these chord changes and really being solid on that root, doing a little bit of walking. The next idea that I want to relate to you is how these chords fit together. And it's really important as we talk about roots and fifths. In really all music, there are three primary chords that we're going to be using and they're based on steps of a scale in a key. Typically, the strongest chords in any key are the one chord, which is based on the root note or the key note. So we've been playing in B-flat. The one chord is the B-flat chord, the chord that starts the tune and ends the tune. So we've been starting on B-flats all along. The second strongest chord in any song, and this goes for rock music, jazz music, any music is what we call the five chord. And it's based on the fifth note of the scale, the fifth that we've been playing. So in B-flat, the B-flat is the one chord and the F chord is the five chord. And you'll notice that that relationship on the bass is a very, very strong one. Now the other primary chord is the four chord and that in the song we've been playing is the E-flat chord. These chords, one chord, in our case the B-flat chord, the four chord, in our case the E-flat chord and the five chord, in this case the F chord, have this strong, strong relationship. And they have this strong sort of geographic relationship on the bass. They fit together really nicely. And that happens for every single key. The one chord, the four chord, and the five chord all fall together very nicely. And incidentally they can be used to harmonize literally any tune. That's why they're so strong in jazz and in pop and in rock music and frankly in classical music as well. So they're all over the place. So it's really important to me that as a bass player you understand the key note is where that root is of the first chord essentially that the four chord is straight across one fret or excuse me one string up on the bass and that the five chord corresponds to the five of the one chord or here. Very, very important this relationship. One chord, four chord, five chord. These will fall together in literally every single jazz tune that you do. The ones in the fives are the strongest relationship. The five always pulls us back to one. And the four is very important as well. So no one chord, four chord, five chord. And we could literally play this blues tune in any key with the knowledge that the one chord is four measures long to start the song. The four chord, the E-flat is two measures, the it goes back to the one chord for two measures, the five chord for two measures, one for one measure, five for one measure. Let's play blues by five one more time and this time instead of calling out the chord names let's use the Roman numeral one, four, or five. And you say them along with me. I think that'll be really important. Here we go. Blues by five. I'll play half notes in B-flat. Playing the one chord to start, one chord, four chord, one chord, five chord, one, five, back to one. Now we could do that same thing in absolutely any key. I think it would be great for us to do it in a different key right now. Let's use the key of G. Now let's play that pattern all in the key of G thinking one chord, four chord, and five chord. You'll see what I'm talking about. Same tune, key of G. Find my G note, roots and fifths. One chord, four chord, one chord, five chord, one chord, five, back to one. One chord, five chord. I hope that makes sense. Work on that and really get used to that relationship between ones, fours, and fives. We'll come into play all through the jazz literature you're going to learn. Good luck.