Wayne Smith's "Under Mi Sleng Teng", produced by King Jammy in 1985 on a Casio MT-40 synthesizer, is a seminal ragga song.
"Sleng Teng" boosted Jammy's popularity immensely, and other producers quickly released their own versions of the riddim, accompanied by dozens of different vocalists.
Ragga heavily influenced early jungle music, and also spawned the syncretistic bhangragga style when fused with bhangra.
The term "raggamuffin" is an intentional misspelling of "ragamuffin", a word that entered the Jamaican Patois lexicon after the British Empire colonized Jamaica in the 17th century.
[1] In the late 1980s, Jamaican deejay Daddy Freddy and Asher D's "Ragamuffin Hip-Hop" became the first multinational single to feature the word "ragga" in its title.