Because it's been a while since I've linked to or discussed something by Atanas Ourkouzounov. Here's a work for solo flute performed by Mie Ogura. Lots of fun extended technique stuff going on in this composition. Atanas is great at exploring extended techniques for a variety of instruments but especially guitar and flute, whether separately or paired. Just on the first couple of pages there's a fun juxtaposition of ornate chromatic descending lines that gets offset by episodes of ascending chains of major sevenths that were, of course, articulated as chains of descending minor seconds earlier in the work. When you're working with what is conventionally a monophonic instrument like the flute that's one of the fun things you can do to establish gestural and registral contrast.
And if you combine vocalized pitches against which the flute's fingering patterns can be contrasted you can open up more multiphonic possibilities, that are explored throughout this work.
The first time I heard a work for solo flute based on extended techniques it was Robert Dick's "Look Out!" which is fun and goofy and the only piece by the composer I can really remember. If you want to get a listen to what that sounds like go over here or here. More than a little affection for Hendrix's Third Stone from the Sun. One thing you may not be able to clearly hear if you don't already know the score for the Dick work is how the opening statement cycles through the overtones that can be brought out from the fundamental tone through controlling the airflow across the instrument. It sounds fantastic live and may be one of the more difficult elements to get across in a recorded/filmed performance. But, of course, the post here is officially about the Ourkouzounov work for solo flute, which I kind of like more because, well, I've always said I've admired his music ever since the start of this blog, haven't I?