Caelestis urbs Jerusalem for five-part mixed choir a cappella was written for the celebration of the seventieth birthday of the architect P.J.H. (Pierre) Cuypers (1827-1921), the leading figure of the neo-Gothic building style in the Netherlands. Diepenbrock called it
an occasional work. (BD IV:140) The composition on the text of a hymn intended for the inauguration of a church was performed by the renowned Klein-Koor A Cappella, conducted by Anton Averkamp, on 16 May 1897. The celebrations took place in the main hall of the Rijksmuseum in Amsterdam, one of Cuypers’ most famous creations.
The choral work sings the praises of the knocking and chiselling of skilled stonemasons who manage to put together all parts of a church “in the right pattern”. It is Diepenbrock’s homage to an architect whose ideas were important in forming his own aesthetics. Cuypers was a member of his mother’s side of the family. As a child Diepenbrock could often be found in his workshop, where he and Cuypers’ son Josef spent Saturday afternoons drawing and he became familiar with architectural principles. Later Diepenbrock said:
There is one thing I learnt from Cuypers that made a huge impression on me as a boy: he said that the Gothic style had the advantage over other building styles that every detail had both a constructive and a decorative value. This gradually taught me to understand music as well. (letter to Antoon Derkinderen, dated 14 February 1894; BD II:150)
The text comprises five strophes of six octosyllabic lines. Diepenbrock based the first and last strophe on the same melodic and harmonic material, some of which is also used in the other strophes.
Characteristic of this homophonic composition are its harmonic changes: in the first sixteen measures there is a modulation from D major to F-sharp major (m. 8), a third relationship (m. 12-13) and a modulation to B major. Later in the piece there are several chord progressions that are derived from the traditional modes.