 
 <prompt> Wetin dey make am hard for AC artists to release Top 40 hits? Based on di previous question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: Mainstream AC don evolve for years; old-time AC artists like Barbra Streisand, the Carpenters, Dionne Warwick, Barry Manilow, John Denver, and Olivia Newton-John dey find am hard to get Top 40 hits as the 1980s dey go on, and because of MTV, artists wey dey popular for Contemporary Hit Radio format, like Richard Marx, Michael Jackson, Bonnie Tyler, George Michael, Phil Collins, and Laura Branigan don dey crossover to the AC charts more often. Collins don be described by AllMusic as "one of the most successful pop and adult contemporary singers of the '80s and beyond". However, with the combination of MTV and AC radio, adult contemporary dey hard to define as a genre, with old soft-rock artists still dey chart pop hits and dey get airplay alongside mainstream radio songs from newer artists at that time. 