Vivaldi’s Fourth Violin is the most difficult, with difficulty levels above ten. "Vivaldi: The Four Seasons" is the first four of Vivaldi's "Twelve Violin Concertos". The composer marked the four seasons of spring, summer, autumn and winter in front of each piece of music, so it is known as "Vivaldi: The Four Seasons". It is logical to name it "Four Seasons". Music is an art form and cultural activity whose medium is timely organized and regular sound waves (a type of mechanical wave). Its basic elements include strength, tonality, duration, timbre, etc. Different types of music may emphasize or ignore some of these elements. Music is performed with a variety of instruments and vocal techniques, and is divided into instrumental music, vocal music (such as songs without instrumental accompaniment), and compositions that combine singing and instruments.