Concert refers to a live music performance with a certain scale. If the band doesn't have enough fans' support, it is impossible to hold such a large-scale concert, because renting a venue as big as a gymnasium or theater usually requires a certain amount of money and fame, and performing in front of tens of thousands of fans is very satisfying, not to mention considerable ticket income (of course, many large-scale performances are free to enter). Concert is a carnival festival for fans.