he seems to be the father of a very grey, rainy type of 12-tone-ish-ness

Pijper was quite a figure. He wanted above everything to be"modern": he mixed polytonality à la Milhaud, thundering rythms à la Sacre-Stravinsky, compactness, French clarity, southern exotica ( tango, rumba, habanera, flirtations with jazz).
Still, Mahler looms large over his orchestral works ( especialy the 3 symphonies) and purists do not like this unusual and heady mix.
I love symphonies 2 & 3, with their enormous orchestras and crazy style combinations.
The 6 symphonic epigrams ,however, are just that... short flashes of orchestral invention..but they seem too brief to really capture one's attention.
The 6 adagio's on the contrary are wonderfully mild and solemn - with a strange Ivesian echo.
The late concerto's for violin and cello and the flute sonata are definitely worth discovering.
His vocal works I don't know well.
Recently two short works (on French texts / Deux ballades de Paul Fort) for female chorus and small orchestra were sung (Dutch radio 4) -
See You Tube :
http://www.youtube.com/watch?v=q6nWOxb8Axs#t=11"Halewijn" is propably his most ambitious creation .
He wasn't able to finish "Merlin" - but it has been recorded.
