Notturno Improvvisazione is a study in repetition (Marimba and Vibraphone) as the ground-work for an improvisation (Bass Clarinet). The idea is to establish and maintain a trance-like groove via the repetitive phrases of the Marimba and Vibraphone. The score is devoid of dynamics in the Percussion parts. The percussionists should take their dynamic cues from the soloist being prudent not to dispel the mood. The Vibes and Marimba should feel like altostratus clouds look; the Clarinet, like the sun or moon piercing them.
While not specifically a Minimalist piece, this nocturne does borrow some obvious ideas from the genre in the construct of the Percussion parts. The Bass Clarinet part conversely is structured as a free improvisation. The clarinetist should play all of the written notes but the judicious soloist can add a dimension to the work with their own improvisations. In improvising, the soloist should remain attentive to the overall dynamic of the written music.
As with the few multiphonics, glissandi, and fluttered notes only suggested in the score, all traditional, modern, and extended techniques are acceptable within improvised segments. There is ample space for the soloist to freely incorporate their own personality into the work always conscientious to let it breathe. Of course, the work may be performed solely as written without any additional improvised passages.