In the first six months of this year, 17 million vinyl records were sold in the United States, generating $467 million in retail revenue, nearly double the amount from the same period in 2020, according to the Recording Industry Association of America. Sixteen million CDs were also sold in the first half of 2021, worth just $205 million. Physical recordings are now just a sliver of the overall music business — streaming is 84 percent of domestic revenue — but they can be a strong indication of fan loyalty, and stars like Taylor Swift and Olivia Rodrigo make vinyl an...