Jazz, largely developed from the blues, originated around the beginning of the 20th century. Improvised jazz singing, called vocalese, is often compared by musicians and music critics to the freestyling of rappers within hip hop. Freestyling has also been said to derive from the art of improvising songs that often distinguishes jazz. Jazz has influenced hip hop greatly throughout its entire history; the scat singing of jazz could be heard in the seminal 1979 old school hip hop song "Rapper's Delight" by the Sugarhill Gang. To this day, jazz musicians such as Herbie Hancock collaborate with rappers, creating a sound that blurs genre lines.