especially his
popes
based on the excellent
Velazquez
Caravaggio
Turner
Breugel
Dali
Friedrich
Giacometti
Ukiyo-e
Philine
Goya
Hodler
Schreiter
Grünewald 
For more of these see WebMuseum: Famous Paintings exhibition or Art "Artchive".
(e.g. Rothko
, Pollock
,
Beuys
)
Other classical classic: Brahms, Vivaldi, Tchaikovsky, Wagner (Tannhäuser only), ...
To listen to these go to Classical MIDI Archives
Other classical pop: Rolling Stones, Pink Floyd, ...
The "music" played by throwing forks into a grand piano (e.g. Stockhausen)