On 2 September 1912, Alphons Diepenbrock celebrated his 50th birthday with family and friends in the Dutch town of Laren. Ten days later, on 12 September, a celebratory concert was given in his honour by the Concertgebouw Orchestra led by Willem Mengelberg, with a programme consisting entirely of works by the dedicatee of the evening: the orchestral suite of music from Marsyas, of De betooverde bron (‘Marsyas, or The Enchanted Spring’); the Vijftiende-eeuwsch bruyloftlied (‘Fifteenth-Century Wedding Song’) and Den Uil (‘The Owl’) for vocal ensemble; the Hymn for Violin and Orchestra; the Overture, Simeon's lofzang (‘Canticle of Simeon’), and the finale to Gijsbrecht van Aemstel; and finally the Hymn to Rembrandt. The performers were among the finest Dutch soloists of the day: the soprano Aaltje Noordewier-Reddingius, alto Pauline de Haan-Manifarges, tenor Jacques van Kempen and bass-baritone Gerard Zalsman. The well-known Dutch actor Willem Royaards recited Vondel's verses in the final scene of Gijsbrecht van Aemstel, and the concert-master Louis Zimmerman played the solo in the Hymn for Violin and Orchestra.

After the concert, Diepenbrock was lauded and received a ‘billfold’ containing 3,500 guilders (supplemented shortly afterwards with another 500, representing a total contemporary value of around £36,000), intended to finance the publication of some of his larger works. A supper followed and lasted until three in the morning, after which Willem Mengelberg, the actor Willem Royaards, composer Cornelis Dopper, administrator Hendrik Freijer (and their wives), as well as the author Balthazar Verhagen, cellist Gérard Hekking and Diepenbrock's youngest sister, Ludgardis, drank champagne for several more hours in the Diepenbrock family home on Johannes Verhulststraat, directly behind the Concertgebouw in Amsterdam. The next day the newspapers were full of enthusiastic praise and reviews.

After such a tribute, one might think that Diepenbrock had achieved success and could rest on his laurels. But nothing could be further from the truth: Diepenbrock often complained of how difficult it was to get by, as in the following letter to a critic, dated 24 September 1915: