There are three bands using the name Cydonia - one psytrance, one an Italian power metal band, and the other a French dark ambient project

1. Cydonia is an Italian power metal band with progressive and
electronic elements. Sometimes it even mixes some nu metal features to this musical melting pot. Cydonia came into being around mid 1998, when Steven Horan suggested teaming up with Martin Harley to form a band. http://www.fortunecity.com/tinpan/rioroad/132/history.html

2. Cydonia is also a famous trance band, featuring Dino Psaras

3. Cydonia is a new Dark Ambient project from Barbarossa Umtrunk (Guetteur de Lune = Baron Von S). Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.