Petr EBEN (1929-2007) is a Czesch composer which has composed a huge corpus for orchestra, choir, piano, chamber music....and many fine organ works among whose two "symphonic poems in several movments", one about Faust, the other one about Job.
Moto ostinato is the 3rd part of a kind of a 4 parts symphony called "Sunday Music", in which it has the role of a scherzo. The composer said that Moto ostinato intends to depict the endless struggle by the Man against the Evil ; so, it's a rather dark scherzo (the score says "Moderato and pesante"), as Malher has composed some. (attached is the kind of picture it can evoke).
Beginning : the atmosphere is rather menacing, on a 3/4 rythm which will pervade all along the piece : quaver quaver- semiquaver semiquaver quaver - semiquaver semiquaver quaver.
the atmosphere seems a bit more calm but the stubborn rythm goes on at LH .
, comes a short trio, with the rythm at the LH and the theme in canon at RH and Ped
, the the tempo becomes more animated, excitement goes growing
a section with some tricky irregular rythms
a kind of a transitional toccata
return of the main theme, first in chords with the rythm at the Pedal, then at the the pedal with the rythm at both hands
the coda, with extraordinary (IMHO) echo effects by alternating quickly 3 keyboards
the very abrupt and crash-bang end .
It's probably - personal and debatable opinion - one of the most fascinating organ works written during the second half of the 20th century, and easy to listen to (no Boulez, here).
The big Marc seems the perfect organ there, as if the work had been composed with this precise organ in the mind. The playing suffers evident flaws (two premature piston pushs, etc..) but, if you like it this piece, you can find many good versions on YouTube.