The Musicanet database is one of the largest database for choral music. Hundreds of thousands of choral pieces are listed there.

MUSICA came into being in 1983 as a project of the Centre d'Art Polyphonique d'Alsace (CAPA) in Strasbourg, France. In 1990, the International Centre for Choral Music (ICCM) joined the project to lend its support for the ambition expressed by the International Federation for Choral Music (IFCM) of creating a comprehensive database of the world's choral music. More than thirty years later, MUSICA has amassed data on almost 200,000 musical scores.

URL examples:

• Composers: https://www.musicanet.org/bdd/en/composer/1-a-kempis-nicolas-jean
• Opus: https://www.musicanet.org/bdd/en/score/143212-puer-natus-in-bethlehem-michael-praetorius

Patterns:

http://musicanet\.org/bdd/en/\d+