Query: Mainstream artists from what decade generally did not have success on the adult contemporary charts?
Context: Unlike the majority of 1980s mainstream singers, the 1990s mainstream pop/R&B singers such as All-4-One, Boyz II Men, Rob Thomas, Christina Aguilera, Backstreet Boys and Savage Garden generally crossed over to the AC charts. Latin pop artists such as Lynda Thomas, Ricky Martin, Marc Anthony, Selena, Enrique Iglesias and Luis Miguel also enjoyed success in the AC charts.