Here are some instances that would prompt a screening test: 1  Youâre sexually active. Everyone who is sexually active (even if youâve only ever had one partner and always use protection) should be screened at some point. 2  Youâre having unprotected sex.
The most important melody in a piece of music is called the theme. The theme of a piece makes up the principal melodic material. Theme is a general term for the basic subject matter in a piece of music. Fast pieces have short themes.
The form of a theme and variations consists of a melody, or theme, followed by variations of that melody. Composers often use theme and variation to write an entire piece or to write one movement of a larger piece. It is most often used in instrumental music.