All through last week’s rehearsals, and the weekend’s bounty of Muziekgebouw/Muziekdagen concerts, I’ve been mindful of my own odd perspective, as someone who approaches contemporary composing via jazz and improvised music. At orchestral concerts in the Grote Zaal Saturday and Sunday, my perceptions were intensely colored by regular preoccupations: like, how the sounds of jazz and improvised music have subtly infiltrated contemporary ‘classical’ music.

The American jazz critic Martin Williams once wrote about the profound effect Louis Armstrong’s trumpet playing had even on classical brass players: how his vibrato affected theirs, and how his powerful high notes shaped everyone’s conception of what the horn’s upper register could and should sound like.

In criticism as in many other fields, you find what you know how to look for. The mushroom expert in the woods sees only mushrooms. And so, at the weekend’s concerts, I zeroed in on details that may have evaded listeners with a big-picture perspective on the architecture of classical forms. Who else sat there, thinking about the (fleeting) jazz influences on Jan Vriend’s composing—like a couple of Modern Jazz Quartet-y vibraphone chords buried in his Echo 13.7? Aspects of the brass writing in Vriend’s Hexameron-Phagocitosis likewise made a case for jazz as part of the background for 20th/21st century composition. It’s not like jazz composers/arrangers have exclusive claim to “pyramid chords” for winds, where notes are added one at a time to the top of a held, increasingly complex harmony. But Vriend’s handsome pyramid chords arrived in the context of brass charts whose phrasing and timing were informed by the propulsive lift of what jazz musicians call swing. (That said, there were also some Hollywoody scoring effects, reminiscent of 1970s TV cop show music.)

And what did the opening of Wim Laman’s Syntopoi—with isolated notes in an atomized sound field—recall so much as the fragmentary ‘pointillism’ of quiet, English-style free improvisation? When Welsh composer Richard Barrett lived in Amsterdam in the 1990s, he wrote (for a book I edited, Bimhuis 25) about how he’d listen to improvisers for their “continuing revitalization of musical vocabularies”—would listen for new ideas and techniques improvisers developed that a composer could use. And that holds true, I’d add, even when composers are unconscious of the influence. It’s not like all those trumpet players swayed by Armstrong were aware of it.

We are all voracious listeners these days: a jazz/improvised music person can still love Ives, Capt. Beefheart, Bahaman guitarist Joseph Spence, Nashville harmonica wizard DeFord Bailey and the thundering horns of the Aluar people of Uganda. Composers, composing, are affected by all sorts of things they hear, one way or another.

In the US, some political pundits say Obama’s victory finally puts an end to the culture wars of the 1960s—but in the Netherlands at least, one aspect of that ’60s legacy is secure: an open-minded and utopian attitude that grew out of musical initiatives like Willem Breuker’s concerts that brought together jazz and classical musicians, and which were organized around a timetable (“At nine, you play this solo by Varese. Seven minutes after nine, we do an improvisation on that. Then you classical guys play your Schubert piece, and I’ll improvise straight through Schubert.”) Or take the Inclusive Concerts promoted by Louis Andriessen and others, mixing music from many genres—Renaissance and improvised music, avant-garde pop—which paved the way for the cross-genre STAMP and Rondom and Rumori series that would follow. The idea being, if you came to the show for one kind of music, you might discover something else you like.

(Broad-based series continue, in various mutated forms: for instance at the annual November Music festival in Den Bosch, this very week: www.novembermusic.net.)

That inclusivity, that willingness to disregard genre divisions, is one of the things that drew me to Dutch music as a subject for a book in the 1990s. In New York, where I’d been living, if you wanted to mix jazz and classical music, first you had to have a debate about whether that was even allowed. In Holland, composers just did it, why not? In the States, Wynton Marsalis and his allies tried to expel Anthony Braxton from the community of jazz musicians, because he let modern composed music influence his writing for his quartet, and also wrote through-composed music for two pianos or four orchestras.

(We heard less about this heresy once Marsalis started getting orchestral commissions. In any case Braxton’s response was the same one Duke Ellington gave when accused of over-reaching with Black, Brown and Beige in the 1940s: if jazz musicians aren’t permitted to do this, then don’t call me a jazz musician—but leave me alone to write the music I need to write.)

By contrast, in Amsterdam you had composers like Guus Janssen (or Theo Loevendie or Misha Mengelberg or Paul Termos) moving back and forth between genres. And as all our ears opened up, more influences came into play. The composition from the Muziekdagen that epitomizes these tendencies for me is Janssen’s Four Songs: as you may know by now, while they were doing a short tour, improvising together, the Chinese mouth organ virtuoso Wu Wei told Guus he’d like to play jazz with a big band one time. Given an opportunity to write for Metropole and a guest soloist, Janssen took up the challenge, and wrote a Brazilian bossa nova into the piece, as well as numerous rhythmic and thematic references to African American music. Asia, Europe, South America, Africa, North America: that’s five continents represented in one little suite.

That willingness to let seemingly alien elements into concert music is a Dutch characteristic for sure. Maarten Altena’s robust writing for strings in his Song Book for Claron McFadden reminded various listeners of Ives, Barber and early Elliott Carter—but there were also those weird moments when industrial-sounding percussion broke through, scrapers and (literal) sandpaper: utterly personal touches that opened up the texture. Similarly, Willem Jeths’ 2004 Seanchai (played by the Holland Symfonia on Sunday) made brief but pivotal use of two giant, ringing cowbells, their sound when struck resonating and dopplering in the room, as percussionists swung them through the air, unsynchronized.

Sometimes those strange elements can be very beautiful—like the subdued, almost phantom electronics on Rozalie Hirs’s resonant Roseherte (which, to judge from the way people were talking about it Sunday, was the breakout hit of the festival).

But there’s also that defiant, dada strain in Dutch music. Misha Mengelberg’s teacher Kees van Baaren used to say any good piece of music should be analyzable. Well then, thought Misha: I will put things in my music that resist analysis. Guus Janssen’s teacher Ton de Leeuw stressed economy of means: use only what you need. But Guus thought, “If you want to compose a piece of mud, what good is economy of means there?”

Of course, cross-genre meetings like those on Friday’s Double Dutch concert were but one aspect of the Muziekdagen. But I’m glad such a vital part of the Dutch music scene was so well represented—of course I am, otherwise I wouldn’t have been invited. And whatever else that hybrid music is, it’s a great hook for promoting Dutch composed music abroad.

Personal moment when I realized how close together different musical streams flow here: Friday, backstage, Claron McFadden sat quietly, readying herself to sing Altena’s difficult songs, when she looked up at me and said: hey—didn’t you do that 25th anniversary book for the Bimhuis?

Where else but here would that happen?

Thanks for having me.