Pièce d’orgue (Petite Pièce) JA 33, AWV 37, December 1932

Two original Jehan Alain handwritten manuscripts of this piece are available to view on the Association Jehan Alain website; PO31 and N4.10. A small fee is charged for access which lasts for one year.
https://www.jehanalain.ch/

ms.‘PO31 Pièce d'orgue’ (M-CA’s HA1)*
– title on cover: ‘Petite Pièce en Sol mineur’.
The title on the first sheet of the score is: ‘Pièce D’orgue’

ms.‘N4.10 Petits prélude, ...’ (M-CA’s HA2)*
– title over score ‘Dec 32 PIECE D’ORGUE’
This ms. includes a full-page drawing in ink by Jehan Alain of an organ console (p.40).

In Jehan Alain’s own catalogue of his works (p.3, no.33)*, he uses the title:
‘Petits prélude, variation et choral p[ou]r orgue’.
A large cross is entered by his title and written below in pencil is: ‘Petite pièce – orgue’.
I am no expert but this handwriting does seem to be very close to that of Albert Alain’s.**

A note from M-CA in her ‘Critical Notes’ (p.107) reads: ‘Petite Pièce (Name by which Jehan Alain called this work when speaking of it.)’.

Albert Alain’s list of Jehan Alain’s works: ‘Pièce en Sol min’ under the title ‘Petites pièces’ for a group of 14 shorter works.

The title used by Helga Schauerte-Maubouet in Volume II of the Bärenreiter Alain urtext edition seems to cover all bases!
Marie-Claire Alain (Leduc) – ‘Petite Pièce’
Marie-Claire Alain (Erato disque) – ‘Petite Pièce’
Helga Schauerte-Maubouet (Bärenreiter, Vol.II)
– ‘Pièce d’orgue (Petite Pièce)’
Helga Schauerte-Maubouet (CD 11303 Motette, Vol.II) – ‘Petite Pièce’