The composer has supplied the following note:
The title Secret Notes seems to make no sense at all, for every separate note is there in the score to read. But what composer could resist a commission from Esa-Pekka Salonen and the Los Angeles Philharmonic New Music Group and would not immediately start composing, or at least brainstorming about such a commission? I certainly wouldn't! As a consequence I got into problems with deadlines of other commissions. Whatever excuses I tried to think of, the truth came out. Perhaps the title won't seem so strange now.
The trombone concerto (Concerto Comique, Opus 17) is the first composition in which I didn't write "notes" any longer. Before, I used to work with themes and motives in a - call it - classical way. In my Opus 17 this changed - and it caused an enormous inner struggle. For the first time I didn't use the unconscious support of composers I admired such as Stravinsky, Copland, Villa-Lobos, Milhaud, and some others. I had been confronted with myself!
Now I am composing in sound colors - you could call them sound tonalities - and I try to find notes (and instruments!) to construct this sound tonality. Which notes they are is of no importance. The obsessive urge to compose a continuum - as in the second part of my Opus 17 - is carried out very strictly in Secret Notes. Each part has its own specific sound tonality with a polyphonic stratification built up from tiny motives that form one big closed whole, as in a mosaic. These independent layers fight a grim battle for the top musical position, as in a concerto grosso from the Baroque. The fragility of these sound tonalities is great: one note too much or too little and the whole composition will collapse like a house of cards.
In my youthful boldness I thought I could easily compose a consonant final part. Dissonance - squirming and strangling - had been a normal practice for me in all my compositions before the trombone concerto. The four-minute-long third part "Leaked Out" is, on the contrary, fully consonant. I was deceived! Every minute that I finished with a struggle doubled my admiration and respect for a master of consonance: Aaron Copland.