Explain how to use trills and shakes on a harmonica for adding expressive elements in blues playing, and demonstrate the proper execution of these techniques.

Trills and shakes are essential techniques for blues harmonica players, adding expressive and rhythmic variations to their playing. These techniques involve rapidly alternating between two notes, creating a shimmering or pulsating effect. While both trills and shakes involve rapid note alternation, their mechanics, sound, and applications in blues music are slightly different. A trill is a rapid alternation between two notes that are close together in pitch, usually a half or whole step apart. The primary mechanism for creating a trill on the harmonica involves rapidly moving the tongue or the mouth, or a combination of both. For instance, to trill between two adjacent holes (for example, the 2 draw and the 3 draw on a C harmonica in second position), the player might use their tongue to rapidly alternate between the holes while keeping the breath steady. Another approach involves slightly moving the whole harmonica back and forth while keeping the mouth still, which makes the airflow change slightly between the two holes that you want to trill. The resulting sound is a fast, clear and distinct alternation between the two notes. Tr....