(Document B) From an advertising poster, it is seen that his concert could hold more than 8,000 seats which at the time cost $1.50, and a few other seats they were $0.75. In the 1920s the US dollar was more valuable than it is today. According to this result, Louis Armstrong was very popular and famous at that time. He also expressed his sad mood in his songs, in "Lonesome Road", "Hotter Than That", "The Snake Rag", "On the Sunny Side of the Street" and so on. For example, in the song "Hotter Than That", Louis Armstrong kept using and repeating the word, "Hotter, hotter, hotter; hotter than hell, hotter than hell, when the sun goes down, a cold day in hell…” He points out that people's lives are evil when they live in hell, and people's mental activity is similar to a war. And, in another Louis Armstrong song: “On the sunny side of street". The lyrics represent beautiful things and "on the sunny side of the street" is repeated several times to express a peaceful and beautiful life. It is a solo for the band and requires the musician to find his own way of explaining jazz, while the musician must put his heart into music. Music comes from life, jazz as a musical form has a profound relationship with social life