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 three and a half octaves of the viola constitute a portion of what musical experts call the chromatic scale. Another way to assess this range is with full note steps, from A to G, disregarding the sharps or flats, in what is called the diatonic scale.