Clues:
A. Gathering work of Schubert? (8)
B. Skim crab soup for Otto (8)
C. Gave credit to workings of a reluctant God (13)
D. Laud Fred's work as shocking (8)
E. Asks after having mass made new in composition of requiems (8)
F. Found out ecstasy can be a cheesy experience (6)
G. Ultimately, flag "not so happy" (6)
H. Hero of Roman arts, creating elegant early pieces (6)
I. Poem is rewritten to be a nuisance (6)
J. Artist from Holland strangely sane within Japan's borders (6)
K. He wore a hood or a mask and odd bits of linen cobbled together (8)
L. Enjoyed pleasure of change ... passed water without friction at start or finish (10)
M. Intend to be harsh (4)
N. Simone Simon in Allegret piece (4)
O. Cross borne in Muppets' revolt, after true revolution (8)
P. Get very worried about mysterious trace of a type of cancer (10)
Q. Wine, Mr Jones? (6)
R. Unusual cases, ones detained by special form of arrest (8)
S. Slice ice, dancing with Mr D (10)
T. Taking drugs: it may lead to your downfall (8)
U. Diners sung wildly, revealing their true selves (10)
V. Invigorating time out on the bottle (4)
W. Separate and succeed today! (6)
X. Devious shark tempts ox - thus he has shown him where to sign (1 5 3 4)
Y. Volleyed up the middle... sound technique! (4)
Z. Relief from the West contributed to his effort according to report (6)