Wonder's breakthrough album, and the first devoid of his original "Little Stevie" persona, Up-Tight gave a promising glimpse of the delights to come. The title track, co-written by the singer, proved a turning point, as Motown had considered dropping him after several previous releases flopped, then his voice broke. In fact the latter development added gravitas, the single became a huge hit and the album was rushed into production, as the occasional vocal fluctuations testify. Another Wonder composition, With a Child's Heart, was later covered by Michael Jackson, while a version of Bob Dylan's protest song Blowin' in the Wind helped him cross over to mainstream audiences and hinted at a blossoming social conscience.
Widely considered to be Wonder's finest record, Innervisions is an uptempo counterpoint to Motown colleague Marvin Gaye's landmark concept album What's Going On, a funky treatise on early-1970s America mixing gritty urban dramas, spiritual anthems, political diatribes and more traditional love songs. Living for the City, replete with an interlude of dark movie-like dialogue about a doomed newcomer to New York, is the dramatic centrepiece, Higher Ground takes transcendental meditation to the dancefloor, while the luscious vocals and piano melody of Misstra Know It All mask a bitter diatribe reportedly aimed at the then US president Richard M Nixon.
Wonder's first platinum-selling album is not considered one of his classics, but shorn of the distracting context (numerous brilliant albums beforehand, several tepid ones afterwards) it holds up as a fine, if slightly flawed, collection. The ballads - All I Do, Rocket Love and Lately - are three of his best, Happy Birthday helped launch a US national holiday and became a celebratory anthem, while the reggae-fuelled Master Blaster (Jammin') and curiously country and western I Ain't Gonna Stand For It were massive global hits.