Kevin Sutton wrote:

>>I have purchased discs of Boulez, Stockhausen, Messiaen, Babbitt,
>>and Carter.
>
>Perhaps a couple of better read folk than I can correct me if I am wrong,
>but I don't regard any of the above mentioned composers as serialist.

According to HH Stuckenschmidt - 20th Music some have dabbled.

Boulez - Polyphonie X 1951 (the structure of this piece and  Structures
for two pianos is outlined in Orientations a collection of Boulez's
writings)
Second Piano Sonata 1948
Structures for two pianos 1952-6

Messiaen - Mode de valeurs et d'intensites (1949)

Michael Hall Leaving Home A conducted tour of 20th music mentions

Stockhausen - Kruezspiel (1951)
Gruppen (1955-7)

Tim Horwood