At first glance, Dave Grohl and Dave Letterman have little in common other than sharing the same first name. While Letterman grew up in Indiana and was married for the first time in 1969, the same year Grohl was born in Ohio, the two eventually became power players in the same decade.
The digital revolution in music has always faced outspoken critics. Some have complained about harsh digital sound. Many lament illegal downloads. These days, musicians protest paltry revenue from streaming sites like Pandora.