Busking (U.S. case law)

In the United States there have been numerous legal cases about regulations and laws that have decided the rights of buskers to perform in public. Most of these laws and regulations have been found to be unconstitutional when challenged. In the US, free speech is considered a fundamental right of every individual, guaranteed by the First and Fourteenth constitutional amendments, and in the majority of legal cases it has been concluded that practicing artistic free speech is legal. Busking is legally considered to be artistic free speech and clearly not panhandling or begging.

Question: is it illegal to busk without a licence
Answer: no