How about 1970?
We can point to something akin to the “invention” of this music (I get it, I get it…there are always predecessors, but these things below arguably crystallized these types of music like nothing prior)
Hip hop
The Last Poets - The Last Poets
Gil Scott-Heron - Small Talk at 125th and Lenox
Punk
The Stooges - Fun House
More overtly aggressive, nasty, loud and confrontational than the previous LP, The Stooges, or anything The Sonics did prior, with perhaps only Monks’ Black Monk Time (‘66) and Velvet Underground’s White Light/White Heat (‘68) to compare.
Listening to Fun House now and comparing it to those others reveals it to have a strong case for first punk LP.
Metal
Black Sabbath - Paranoid
Led Zeppelin - “Immigrant Song” single
While not necessarily music for which a strong argument could be made as to its “invention” in 1970, the music being released by a plethora of jazz and classical artists in 1970 was very often extremely inventive and original.
Miles Davis - Bitches Brew
Steve Reich - Four Organs / Phase Patterns
Pharoah Sanders - Deaf Dumb Blind (Summun Bukmun Umyun)
György Ligeti - Chamber Concerto
Art Ensemble of Chicago - Les Stances a Sophie soundtrack
Alice Coltrane - Ptah, the El Daoud
Karlheinz Stockhausen - Opus 1970
Sonny Sharrock - Monkey-Pockie-Boo
McCoy Turner - Expansions
Then 1970 gave us whatever the heck ya call this music:
Captain Beefheart & the Magic Band - Lick My Decals Off, Baby
Kraftwerk - Kraftwerk
Nico - Desertshore
Armando Sciascia - Impressions in Rhythm & Sound
The Group - The Feed-back (featuring a young Ennio Morricone)
Can - “Don’t Turn the Light On, Leave Me Alone,” “Tango Whiskeyman,” “Mother Sky”
Popular music was doing pretty well.
Stevie Wonder - Signed, Sealed & Delivered
Harry Nilsson - Nilsson Sings Newman
James Brown - Sex Machine
Randy Newman - 12 Songs
The Delfonics - The Delfonics
The Velvet Underground - Loaded
Minnie Ripperton - Come to My Garden
Nick Drake - Bryter Layter
Band of Gypsys - Band of Gypsys
Frank Sinatra - Watertown
Donny Hathaway - Everything is Everything
Joni Mitchell - Ladies of the Canyon
The Chi-Lites - I Like Your Lovin’ (Do You Like Mine?)
Led Zeppelin - Led Zeppelin III
Neil Young - After the Gold Rush
Performance soundtrack
George Harrison - All Things Must Pass
Creedence Clearwater Revival - Cosmo’s Factory, “Have You Ever Seen the Rain”
David Bowie - The Man Who Sold the World, “Conversation Piece,” “The Prettiest Star”
Elton John - Tumbleweed Connection, “Border Song,” “Your Song”
John Lennon - Plastic Ono Band, “Instant Karma!”
Gladys Knight & the Pips - “If I Were Your Woman”
The Jackson 5 - “ABC,” “I’ll Be There”
The Carpenters - “We’ve Only Just Begun,” “(They Long to Be) Close to You”
Edison Lighthouse- “Love Grows Where My Rosemary Goes”
The Spinners - “It’s a Shame”
The Temptations - “Ball of Confusion”
The Four Tops - “Still Water”
Don McLean - “Castles in the Air”
Led Zeppelin - “Hey Hey What Can I Do”
Beatles - “Let it Be,” “You Know My Name (Look Up the Number)”