"Clair de lune" (moonlight) is in the 2nd Suite de pièces de fantaisie op.53. It's a great nocturne where Vierne is at his best in the serene and lyrical mood, without the acerbic or dark tone present in so many of his pieces. It's at par with pieces like Arabesque, Adagio from 3rd symphony or Romance from 4th symphony.
Clair de lune is in D flat major, the tonality par excellence for Nocturnes (as Debussy's Clair de lune, Fauré's 6th nocturne or Liszt's Harmonies du soir...). It's constructed as follows :
: the aetheral first theme on the GT flûte harmonique accompanied by the SW gambe
: the atmosphere becomes more animated with the 2nd theme in the tenor like a cello song, played at the pedal with 8'
: the second theme goes to RH, accompanied by LH arpeggios and the animation increases
: return of serenity with the re-exposition of the first theme (flûte harmonique and voix céleste).
There are some registrations problems for this piece at Oloron : pedal flues a bit loud (because there is only a 16' and a 8', so they are an all purpose compromise), Récit a bit weak for the third part (the LH arpeggios are difficult to hear)...But Oloron's splendid flute harmonique is enough to make the experience rewarding.