Joseph Callaerts (22 August 1838 – 3 March 1901) was a Belgian organist, carilloneur, composer and music teacher. He was an important member of the Belgian school of organ playing. He was born in 1838 in Antwerp, and spent nearly all of his life in that city. He started learning music when he was a boy, singing in Antwerp's choir of the Cathedral of Our Lady. As a young man, he studied the organ with Jacques-Nicolas Lemmens at the Brussels Royal Conservatoire, and he won the first prize in organ at that institution in 1856.
Starting in 1850, Callaerts served as the organist at the Jesuit College in Antwerp. In 1855 he became the organist at Antwerp Cathedral and in 1863 he became carilloneur of the city of Antwerp. From 1867 on, he taught organ and harmony at the Royal Conservatoire of Antwerp, which had its name changed to the Royal Flemish Conservatoire in 1898. He also gave expert advice in the building of several organs.
Callaerts's compositions include an opera called Le Retour imprévu, a symphony, a piano concerto, an organ concerto, a violin and orchestra concert piece, chamber music, choral music, songs and many works for solo organ and solo piano.
"Adoration", the 1st piece in the Opus 21 set, has the nature of an intimate and melodic prayer. It has the feel of an act of devotion about it, emotional, with a touch of divine sentimentality about it.
The work is dedicated to Callaert's friend, D. van Reyscchoot, organiste de l,Eglise St. Nicolas a Gand.
The score is attached below, as well as a photo of Joseph Callaerts, several of Antwerp Cathedral, where the composer was organist, and several of St. Nicolas Church, where the dedicatee was organist.
You can find the other movements from this book here:
"Canzona, Op. 21, No. 5"
https://www.contrebombarde.com/concerthall/music/19487
"Sortie Solennelle, Op. 21, No. 6"
https://www.contrebombarde.com/concerthall/music/19488