Arvo Part? This is his Te Deum.
[video=youtube;CPd3e5woOyc]https://www.youtube.com/watch?v=CPd3e5woOyc[/video]
One of his musical devices has been described (I don't recall if he named it as such, or someone else did) as "tintinambulation;" named after the tolling of bells. His harmonic pallet mimics traditional cathedral bell tunings and pairings: the reason bells sound so clearly is that the 2nd partial (the 5th) sounds considerably stronger than even the fundamental pitch or the 1st partial (the octave). So, in mimicking the sounds of bells, composers will double the 5th of a chord and often omit the 3rd. This is compounded when stacking "open 5ths." So, whenever you hear an ambiguous "hollow" sounding group of notes, that simultaneously is very strong, that is probably what is going on. Edit for guitarists: this is what's going on with "power chords;" you're playing the root, 5th, and octave, while omiting the 3rd (which is what gives chords the minor/major designation)...which is why you can just strum whatever power chord you want, wherever you want, and it will sound just fine (because it's ill-defined as a structural entity [Allen Forte would identify those as 07...a rant for another time]).
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