Rehearsal of the Interludes at WRAP. From left to right: Jostein Gundersen on prepared recorder, Hans Lub, Mikko Perkola, Hans Knut Sveen.

The singers and organetto took over the harmonic interpolation for the second interlude. Each chose a line and empasized microtonal interferences and dissonances.

Bass recorder, 2 fidels and viola da gamba performed continous figurations based on Codex Faenza, at different speeds, detuned, displaced fingering positions, or transposed to create obscure murmuring sounds. Overall identities were narrowed down, while the performers became composers putting together the exact details.

Two types of interludes were performed in the concert. The score contains a plain interpolation between partials of a deep E flat to a transposed, pitchshifted spectrum with another partial order. Early works of Tristan Murail like "Desintegrations" 1 uses such interpolations of overtone series. With a basis in phenomena of timbre or instrumental models, a process of distortion is introduced. This was, if you like, a spectral music etude for a medieval ensemble.

Two different interludes are suggested through text instructions. In the first interlude fidels, and organetto perform the interpolations with a model of quick attack and slow individual decay, timbral and gestural activity, iteration, oscillations and fluctuations within those chords. This model was inspired by the gradual "pollution" of the spectrum in the beginning of Gerard Griseys "Partiels". 2

The alto recorder should perform rapid diminutions based on Codex Faenza, with obscure sonorities. Jostein prepared his recorder with tin foil, and we agreed on a soft shimmering sound with occasional loud, unpredictable outbursts making the foil vibrate for buzzing sounds.