When Siegfried Jung, Tubist at the Mannheim Opera House asked me to compose a piece for tuba, harp and orchestra (his wife being a harpist), I felt greatly honoured by the faith and trust in me this meant. At the same time, this commission also meant a great challenge, as the tuba as a soloist was at the time quite new to me.
In the many hours thus spent in Mr Jung’s rehearsal room, to form a better understanding of the facilities of the tuba, I was amazed to witness the tender and even melancholy expression of the instrument, especially in the higher pitches. The sound at times seemed gentle and vulnerable to me, diametrically opposed to what is the general expectation of the tuba.
I quickly resolved to make sure that my composition would illustrate all and every tonal facet of the tuba. And in my orchestration I followed the instrumentation of the tuba concert by Vaughn-Williams, who, for good reason, and allowing for the more reserved dynamics of the tuba in the higher pitches, makes use of a reduced woodwind and brass arrangement (2-1-2-1 and 2-2-2 respectively) 
What is more, I decided that trombones would be absent from my composition, in order to be able to afford the tuba sufficient space.
The first movement of my Divertimento bears the title "Toccatina giocosa". It is defined by dynamic quaver motions of all sections of the orchestra. Nevertheless, the composition prances nimbly throughout, while the tuba’s versatility amazes. Tuba and harp enter into a musical dialogue time and again, and the listener will recognize immediately that what may initially seem to be a mismatch actually makes a perfect synergy. Contrasting with the continuously pulsating quavers the elaborate melodic themes develop at the same time.
The second movement "Paesaggio" displays the entire range of the tuba‘s lyrical-expressive hues. After an introductory ostinato motion of the woodwind section, the tuba performs a sustained theme of a wide cantilena, which in its course leads up to, and dramatically peaks in, a cadenza of the two solo instruments. After a spectacular treble C (which I only dared include on express wish of the commissioner, who knows how to present it in a breathtaking manner) the tuba then leads over to a cheerful little waltz, detaching temporarily from the melancholy mood of the beginning. After this brief interlude the movement returns to its original character and ends in the ostinato woodwind routine familiar from the introduction, accompanied by a regular repetition of the C by the harp as flageolet.
In the third movement, "Zwiefacher", the tuba returns to for what it is really most clearly perceived and remembered: And that is a forceful bass instrument, especially in folk music. For this movement I purposefully chose a "Zwiefacher” structure. The “Zwiefacher” is a traditional folk dance, popular in Bavaria (Southern Germany), which alternates between 3/4 and 2/4 time signatures and in 2016 was included in the German Intangible Cultural Heritage List. In the introduction to the movement the tuba sets in with a cheerful solo without recognizable accompanying harmony. A bit like walking home tipsy. In the repetition of the motif the harp joins in, however, not in its orchestral elegance, but as a mere accompaniment, as it is common for folk music. Finally, the entire orchestra joins into the hearty burlesque attitude. In the middle part the tuba bridges, with elongated notes, the agitated and ever-changing rhythms and added dizzying changes in harmony. The movement ends in a Stretta reminiscing on the main motif of the Toccatina, together with another change of beat. After two bars each in 3/4 and 2/4 so far, it picks up even more speed by now switching beats every bar, to culminate in a grotesque final 1/4 time bar.
The intense and pleasant cooperation with Johanna and Siegfried Jung will remain a fond memory of mine, so will the outstanding orchestra of the Mannheim Opera House and the careful and nuanced musical direction by Prof. Walter Hilgers during the recording of a CD-project for the “Coviello" label.