MMario--I'm not after your money, but I had a chance, a while back to sit in with three of Frank Valli's   singing chums from the Jersey street corner days, and they made it very clear that they had sung doo-wop because it was what people wanted to hear, and that even in those old days, they could also do Four Freshman type stuff(They made me sing melody, which requires no specially skill in a vocal group, outside of getting the notes right, but meant that I could hang in there even when the did Blue World and Graduation Day)--In reading through some of the Doo-wop sites, it seems that it was not uncommon for R&B vocal groups to "De-Evolve" from more sophisticated stuff to Doo-wop--