Modern music uses ambiguous chord sequences - usually four chords - that repeat over and over but never come to a climax or a pause. The chords are ambiguous be

Modern music uses ambiguous chord sequences - usually four chords - that repeat over and over but never come to a climax or a pause. The chords are ambiguous because they fit with a couple of keys - usually related major and minor, or perhaps a mode - but without the stops there's no clear sense which applies. I don't agree with that. A key is not just a collection of allowed notes, there is a kindof frequency distribution to them too, so that the tonic is either the most used or the most implied. The fifth is often the second-most-used. Its sortof like a key has a 'center of gravity' in the tonic note. Either it will be used a lot or alluded to a lot. So a chord sequence might technically fit into different keys but usually there is an implied tonic and that 'tells' you what key you are in. So within a (well constructed) chord sequence in modern pop you can still have suspense and resolutions and so on. Kindof the same as cadence but done in a different way. And the trick to a good key change is to subtely shift the 'weight' in the direction of the new key just before you make the change.