Doug E. Fresh & Stevie Wonder 

This video is about the Obama Blvd Celebration featuring closing artists Doug E.Fresh and a surprise appearance by Stevie Wonder doing an acapella medley with the "Human Beatbox" Doug E. Fresh.
Douglas Davis, better known by his stage name Doug E. Fresh (born September 17, 1966), is a Barbadian-American rapper, record producer and beatboxer, also known as the "Human Beat Box". The pioneer of 20th-century American beatboxing, Fresh is able to accurately imitate drum machines and various special effects using only his mouth, lips, gums, throat, tongue and a microphone.
Doug E. Fresh began his recording career as a solo artist; he was among the last artists on Enjoy Records and one of the first on Vintertainment Records (the same New York-based label owned by Vincent Davis that would later make a name of hip-hop artist Joeski Love and bring R&B singer Keith Sweat to ultimate fame). He and a new team of DJs known as the Get Fresh Crew (Barry Bee and Chill Will), along with newcomer MC Ricky D (who would later achieve fame as Slick Rick), came to fledgling New Jersey-based hip-hop label Danya/Reality Records the following year and recorded "The Show", which borrowed the melody of the Inspector Gadget theme by Shuki Levy. They also recorded "La Di Da Di", a tune that was completely voiced by MC Ricky D and backed by Doug E. Fresh's beatboxing for the entire duration of the song. The release of these two songs as a 12" single launched Doug E. Fresh (and Slick Rick) into stardom. Both songs are considered among the greatest early hip-hop classics. "The Show" peaked at #7 on the UK Singles Chart in December 1985.
Stevland Hardaway Morris (né Judkins; born May 13, 1950), better known by his stage name Stevie Wonder, is an American singer, songwriter, musician, and record producer. A prominent figure in popular music, he is one of the most successful musicians of the 20th century. Wonder's "classic period", between 1972 and 1977, is noted for his funky keyboard style, personal control of production, and series of songs integrated with one another to make a concept album.
Blind since shortly after his birth, Wonder was a child prodigy known as Little Stevie Wonder leading him to sign with Motown's Tamla label at the age of 11. In 1963, the single "Fingertips" was a No. 1 hit on the US Billboard Hot 100 when Wonder was aged 13, making him the youngest artist ever to top the chart.