Can't speak for the whole book but if the egregious error in the entry for the 1950s Drifters is any indication it seems to have been carelessly scraped together from other sources. Rosalsky states (p. 169) that after Bill Pinkney was fired "the Drifters now consisted of Bobby Hendricks... Dee Ernie Bailey and Billy Kennedy..." In fact, neither Bailey nor Kennedy were ever with the Drifters; rather they had been (with Hendricks) in the Flyers, the group Pinkney put together after he was fired the first time. Then he was rehired as a Drifter briefly and recruited his ex-Flyer friend Hendricks to the Drifters (to replace the drafted Johnny Moore) before being fired a second time. But Bailey and Kennedy were only Flyers, never Drifters.
Caveat emptor.