Concurrently, African-American popular musicians drew from progressive rock's conceptual album-oriented approach. This led to a progressive-soul movement in the 1970s that inspired a newfound sophisticated musicality and ambitious lyricism in black pop. Among these musicians were Sly Stone, Stevie Wonder, Marvin Gaye, Curtis Mayfield, and George Clinton. In discussing the development, Martin cites 1970s albums by Wonder ("Talking Book", "Innervisions", "Songs in the Key of Life"), War ("All Day Music", "The World Is a Ghetto", "War Live"), and the Isley Brothers ("3 + 3"), while noting that the Who's progressive rock-influenced "Who Are You" (1978) also drew from the soul variant. Dominic Maxwell of "The Times" calls Wonder's mid 1970s albums "prog soul of the highest order, pushing the form yet always heartfelt, ambitious and listenable".