Mariah Carey
It involves songwriting Olympic-level vocal gymnastics (she famously has a 5-octave variety) and game-changing artistic dangers (her catalog of R&B, hip-hop, and dance-music remixes is still the gold common to which all musical acts aspire). She is the only artist to have had a No. 1 single in each of the previous 4 decades, and, with 145 million albums sold,...