The question itself is rather subjective hence the 1st person pronoun. However, I believe that many of you reading this question agree with me and hear 'Bb major'. If you hear it in a different way, please comment on it. That could also be a survey.
The following measures are from the last movement of Trilogy Sonata by Philip Glass. It's an arrangement, so the piece was not written for the piano originally. But, it's not just 'another' arrangement; the composer himself knows about this arrangement. I also re-wrote it on Sibelius and played with the help of NotePerformer, and I captured my screen. So you can listen to the measures on loop.
As you see, we have D natural and D flat in the same measure, and the same 'trick' continues for two measures. I first listened to the piece without the score, then when I looked at the score I was simply shocked. We have both D major and D flat in the same measure -which makes the chord both Bb major and Bb minor- and I heard (and I still do) it as Bb major, despite the D flat tone(tone=note).
How is that possible? I think the primary reason is the excellent voicing and the fast tempo. But I've never encountered such a thing before -except in Glass's other works.- How can we explain this aesthetic approach? What is the reason that we don't lose the sense of tonality here?
Here's the video