2. In this chapter, you learned that some pathogens must attach to host cells to cause disease. To accomplish this, molecules on their surface (adhesins or ligands) recognize and attach to molecules (receptors or integrins) on the surface on certain host cells.
So a chromatic note, is any note you play that is not in the scale you are playing. They are also a great way to practice, especially if you are going through the pentatonic scale. Try adding one of these outside chromatic notes to your scale, and see how it sounds above the chord you are playing over.
The chromatic harmonica was invented by HOHNER more than 100 years ago. As the name suggests, it contains all natural notes plus all sharps and flats, thus enabling chromatic melodies. Basically the chromatic harmonica consists of two harmonicas, one in C and one in C#, separated from one another by the slide, which is operated by the button at the side. When the slide is not used, the instrument is in C major and only the white notes on the piano keyboard are available.