Natural references in his compositions include the frozen Engadin Lake Sils in Sils, Opus 1, the clicking of insect stridulation in Siegel (Seal), Opus 3, the breathing rhythms of a woman in labour in Die Atmer der Lydia (Lydia’s Groans) Opus 5, the sounds of a large city in Im Dschungel (In the Jungle) Opus 6, and waves, landing aircraft and white noise in Klavierkonzert (Piano Concerto), Opus 9.
Declamation of text is a prominent feature in several works, including Arbeitslieder (Work Songs) Opus 8, Solde (For Sale) , Opus 10, Joyce-Fantasie, Opus 13 and Istanbul, Opus 14. Delz used early music as a model for Nocturnes, Opus 11, and specifically J. S. Bach’s E major Preludio, BWV 1006/1 in Streichquartett (String Quartet), Opus 7, and Bach chorales in Jahreszeiten (Seasons), Opus 12 and in Istanbul, Opus 14.