KRS-One is considered to be a pioneer of rap. He was a leader in the hip-hop movement of the 1980s as a member of the rap group Boogie Down Productions. KRS-One's music is filled with messages and contains more substance that many of the rappers that would follow his lyrical lead. KRS received his nickname "The Teacher" due to the political insights and well-presented arguments that appears throughout his discography.KRS and BDP were well-respected until some fans thought the confident frontman was doing more preaching than teaching on the group's 1990 disc Edutainment. KRS's first solo effort, 1993's Return of the Boom Bap, featured a much harder sound in what was likely an attempt by KRS to regain some of the street credit that was lost due to fans' qualms with Edutainment. The album though, could not stave off what appeared to be a decline in KRS's commercial appeal on a large scale. He followed up his solo debut with a self-titled album in '95 and dropped Battle for Rap Supremacy, a collaboration with a former rival MC, the following year along with I Got Next.KRS took a break from his solo career until 2001's The Sneak Attack, which came equipped with the same confident, brash attitude that he'd always exuded, proclaiming himself the God of hip-hop. He asserts the notion that he's one of the fathers of rap with lyrics like "I'm the teacher, but you still can't see/'Cause while you respected Tupac, Tupac respected me."Always taking pride in lyrically bashing fellow artists, KRS showed that he wasn't too old for feuds in 2002 when he attacked rapper Nelly on The Mix Tape. The feud actually put KRS-One back on the map in some eyes as he'd taken a back seat to most mainstream rap artists at that point. While his old-school sound doesn't appeal to the masses the way it did in the ‘80s, KRS has continued to release both collaborative and solo albums on a regular basis.