Gabor Steiner Verlag publishes Koffler's arrangements for voice and piano of songs from the singspiel Mozart (premiered on 2 June 1923 at Vienna’s Volksoper, libretto: Julius Wilhelm and Paul Frank, music: Hans Duhan).
Koffler addresses the Professorial Board of the Faculty of Philosophy at the University of Vienna, requesting admission to doctoral exams. In his application he informs that he had studied composition with Josef Foerster in Prague.
Koffler passes his doctoral examinations, approved jointly: in Polish literature with Nikolay Trubetskoy (mark: ‘gut’), in musicology with Guido Adler and Robert Lach (mark: ‘genügend’), in philosophical subjects with Karl Bühler (psychology) and Robert Reininger (philosophy) (mark: ‘genügend’).
His doctoral dissertation is titled Die orchestrale Koloristik in den symphonischen Werken von Mendelssohn [Orchestral Colours in Symphonic Works by Mendelssohn]. In his review, Robert Lach wrote: ‘The author attempts to explain the concept of sound colour on the basis of physical research into its nature.’
Koffler signs his promotion to Doctor of Philosophy (in the field of musicology).
He remains in Vienna most likely till the summer of 1924.