Old school hip hop (also spelled "old skool") describes the earliest commercially recorded hip hop music (approximately from 1979–1984), and the music in the period preceding it from which it was directly descended. Old school hip hop is said to end around 1983 or 1984 with the emergence of Run–D.M.C., the first new school hip hop group. However, some old school rap stations cover 1980s hip hop in general, occasionally extending even into the mid 1990s.