It is very unlikely that this work is public domain in the EU, or in any country where the copyright term is life-plus-70 years. However, it is in the public domain in Canada (where IMSLP is hosted) and other countries where the term is life-plus-50 years (such as China, Japan, Korea and many others worldwide). As this work was first published before 1927 or failed to meet notice or renewal requirements to secure statutory copyright with no "restoration" under the GATT amendments, it is very likely to be public domain in the USA as well.
|Genre Categories||; ; ;; ; ;|
|Work Title||Mater ora filium|
|Alternative. Title||Mater, Ora Filium. (Carol from a Manuscript at Balliol College, Oxford.) For unaccompanied double choir.|
|Opus/Catalogue NumberOp./Cat. No.||GP 246|
|I-Catalogue NumberI-Cat. No.||IAB 22|
|Year/Date of CompositionY/D of Comp.||1921|
|Language||Latin and English|
|Dedication||To C. Kennedy Scott|
|Composer Time PeriodComp. Period||Early 20th century|
|Piece Style||Early 20th century|
|Instrumentation||2 mixed choruses (SATB/SATB)|
Wikipedia article (Dutch)
There seem to be editions published in 1921 also?