I'm very fond of the section "Les Bergers" from La Nativite du Seigneur of Messiaen. Especially the section that starts at bar 58, which is 3.00 on the video attached. It shows the score. There is a repeated cadence which ends in A minor in the bass. However at bar 65 the melody plays Ab, Bb, C as if it were in Ab major. It's a strange sound but somehow makes sense and it gets into your head. Try playing the passage with the score and you'll see what I mean.