Sometimes in music we see that the normal accents are moving to another place.
Such a shift of accent we call a syncope. The word syncope comes from the Greek word συγκοπή (sincopí).
When we tie a note with an accent to a previous note without accent, we have a syncope. In fact we skip the place with the accent.
The Greek word sincopí is about the heart, skipping a beat, that's something we don't want to happen. But a syncope in music
makes a beautiful exiting effect in the rhythm and the melody.
In both following examples you see above the notes the accents as they are normally.
Underneath you see the accents because of the ties, so the syncopes.
In example nr. 1 the tied c is moving the accent from the 1st beat of bar nr. 2,
to the 4th beat of bar nr. 1. One bar later, the same thing happens,
but now the accent goes to the second half of the 4th beat.
In example nr. 2 the tied d is moving the accent from the 1st beat of bar nr. 2 to the 3rd beat of bar nr. 1.
There are syncopes is all kinds of music, in pop- and jazz music aswell as in classical music.