Chris Dalla Riva: How did contemporary musical world become dominated by vocalists?

"[Nowadays] It feels like if you have a musical group it must be centered around the vocalist. If we measure the average percent of instrumental content per Billboard number hit between 1940 and 2021, we see demonstrable evidence for not just the decline of the instrumental superstar but the instrumentalist generally, with the sharpest declines beginning in the 1950s and the 1990s" - Chris Dalla Riva points out. He offers an explanation: "I believe it comes down to four factors: improved technology, the 1942 musicians’ strike, WWII, television, and hip-hop."