Rather sorry to have missed
this.
Ooops! Sorry, forgot I had already posted
here. I tried to delete this one, but was not allowed to. One cannot delete one's own topics, it seems, only one's replies.
Well, this one seems to have got more replies so far (albeit somewhat off-topic)!
Aaron Copland - Fanfare For The Common Man
John Cage - Triple Paced
Miles Davis - Concierto De Aranjuez
Steve Reich - Come Out
Jan Garbarek & Hilliard Ensemble - Parce Mihi Dominum
Michael Nyman - Wheelbarrow Walk 2
Gavin Bryars - Tramp With Full Orchestra
Morton Feldman - Voices And Cello
Lou Harrison - Threnody
Glenn Branca - Symphony No 10 (first movement)
Steve Martland - Principia
Howard Skempton - Well, Well, Cornelius
Cornelius Cardew - Revolution Is The Main Trend
Giacinto Scelsi - Quays For Alto Flute
Gyorgy Ligeti - Lux Aeterna
Gorecki - Three Olden Style Pieces
Edgard Varese - Deserts (Excerpt)
Xenakis - Kraanerg (excerpt)
Frank Zappa - Jonestown
Keith Jarrett - Adagio For Oboe And String Orchestra
Charles Ives - Central Park In The Dark
Philip Glass - Knee Play 1
Chris Fitkin - Sextet
Graham Fitkin - Cud
Michael Tippett - Blue Guitar 3
Toru Takemitsu - Sacrifice
La Monte Young - Day Of Niagra 1955 (Excerpt)
La Monte Young - The Well-Tuned Piano (Excerpt)
Richard Rodney Bennett - Fridays Child
Isao Tomita - The Girl With The Flaxen Hair
Stockhausen - Helicopter String Quartet Ascent: Ignition Of The Turbines (excerpt)
Elvis Costello & The Brodsky Quartet - The Birds Will Still Be Singing
Terry Riley - The Chord Of War
Arvo Part - Spiegel Im Spiegel
As 'popular classics' go that's a pretty good list!