3 sites have this keyword listed in their metadata, here's one you may hate:
A composition that when the first half of it is reversed and played immediately after itself it becomes the second half of the melody without being glaring or obvious. (Basically, if you save this and play it in reverse, it will be the exact same song.)
Other sites with this keyword...
|?Faerie's Aire and Death Waltz||jazzydan||870||(3.48)|