Modal interchange

Modal interchange is when you take notes or chords from one scale and use them in another. It's like when you have two boxes of crayons, but you decide to use some of the crayons from one box in your drawing with the other box.

For example, let's say you're playing a song in C major, which has the notes C, D, E, F, G, A, and B. But then you decide to use a chord from C minor, which has the notes C, D, Eb, F, G, Ab, and Bb. You might use the Eb chord, which has the notes Eb, G, and Bb. That chord doesn't normally show up in C major, but it sounds really cool when you use it.

Modal interchange can make your music sound more interesting and complex. It's like using different colors in your drawing to make it more vibrant and exciting. And just like with crayons, you have to know which notes or chords will work well together in order to create something beautiful.