According to music writer Peter Shapiro, the term itself refers to a musical style that obtains its influence from older R&B styles, and bohemian musicians seeking a soul revival, while setting themselves apart from the more contemporary sounds of their mainstream R&B counterparts. In a 1998 article on neo soul, "Time" journalist Christopher John Farley wrote that singers such as Hill, D'Angelo, and Maxwell "share a willingness to challenge musical orthodoxy". Miles Marshall Lewis commented that 1990s neo soul "owed its to '70s soul superstars like Marvin Gaye and Stevie Wonder", adding that "in concert, Erykah Badu and D'Angelo regularly covered Chaka Khan, the Ohio Players, and Al Green, to make the lineage crystal clear." In citing Tony! Toni! Tone! as progenitors of the genre, Tony Green of "Vibe" viewed that the group pioneered the "digital-analog hybrid sound" of neo soul and "dramatically refreshed the digitalized wasteland that was R&B in the late '80s". Neo soul artists during the 1990s were heavily inspired by the eclectic sound and mellow instrumentation of Gil Scott-Heron's and Brian Jackson's collaborative work in the 1970s. "All About Jazz" cited Jackson as "one of the early architects" of the sound and his early work with Scott-Heron as "an inspirational and musical Rosetta stone for the neo-soul movement".