Here is the new full list of genres. We are still lacking many World Music categories, and 78RPM probably needs some specialised categories of its own.
Alternative
Ambient
Americana
AOR
Avant Garde
Balearic
Beat
Big Band
Black Metal
Blues
Bollywood
Bossa Nova
Brass & Military
Breaks & Beats
Bubblegum
Calypso
Chanson
Childrens
Christmas
Classical
Comedy
Cosmic
Country
Dance
Dancehall
Deep Soul
Delta Blues
Disco
Disco Boogie
Dixieland
Doo Wop
Downtempo
Drum & Bass
Dub
Easy Listening
Electronic
Emo
Esoteric
Exotica
Experimental
Folk
Freakbeat
Free Jazz
Funk
Fusion
Garage Punk
Girl Group
Glam
Gospel
Goth
Grunge
Hard Bop
Hard Rock
Hardcore
Heavy Metal
Hip-Hop
House
Indie
Industrial
Instrumental
Italo Disco
J-Pop
Jazz
Junkshop Glam
K-Pop
Krautrock
Latin
Library Music
Lovers Rock
Minimal
Mod
Musicals
New Age
New Wave
Noise
Non-Music
Northern Soul
Novelty
NWOBHM
Opera
Polka
Pop
Popcorn
Popsike
Post Punk
Power Pop
Progressive
Psychedelic
Psychobilly
Punk
Reggae
Religious
Revival
Rhythm & Blues
Rock
Rock & Roll
Rockabilly
Rocksteady
Roots Reggae
Schlager
Shoegaze
Singer Songwriter
Ska
Soft Rock
Soul
Soundtrack
Spiritual Jazz
Spoken Word
Stage & Screen
Stoner
Surf
Swing
Synth
Techno
Traditional
Trance
US Roots
Video Games
Vocal
World
Nice to see Opera added to the list. I'd like to see 'Symphonic' or "Orchestral' for Classical music - 'Instrumental' is a better fit for solo or small ensemble works.