So this is how it works. With any harmony, there are questions one or two that you have to ask, to determine the right chord scale. Let's take the easiest example, let's say it's just a major chord. it's a major harmony, let's say it's C major 7. remember the scales we talked about last week. Up, among the 10 most common scales, there were two major scales involved. There was the Ionian [SOUND], and the I, and the Lydian [SOUND]. The difference is in the fourth degree. The Ionian has a natural 4, the Lydian has a raised 4. So if you come to a major, C major 7 chord in a piece of music you have to answer the question is it a natural 4 or a raised 4? Or in other words is it an F natural or F sharp? And then you'll know which of the 2 scales is the right one for that measure. And here's how you find the answer. first you look at what you see in front of you. Look at the written music. Half the time, the note in question will be right there in the written melody of the song. So if you see an F sharp, [SOUND]. Then you know, [SOUND] it's Lydian. If you see an F natural, [SOUND] you know it's Ionian. if you don't have written melody in front you. Sometimes, like, you may be playing a big band chart and all you have are chord symbols. or, if the note in question that F or F sharp doesn't appear in the written melody. Then we find the answer to the question by looking at the preceding chord scale, the harmony before the one we're looking at. And you'll find the note there. It'll, you'll find that F natural or F sharp in the preceding chord. So using the most common example of going G7, [SOUND], to see. We see that [SOUND] there's an F natural in the G7 chord, [SOUND] and that's going to influence the C Major chord to be Ionian. Whatever is ringing in the harmony, wants to continue ringing into the next harmony if it can. If something forces it to change because the chord symbol requires it, that's another story. But if nothing forces it to change, then any note that's ringing wants to continue on into the next harmony, and it's going to influence it. So that's [SOUND], that's how we answer that question. So there's two ways to answer the question. It's either, visible in the written notes that you see in front of you or you look at the at the preceding cord scale and use that as an indicator.