Thalassa was a specially formed for the Euro Vision Song Contest Pop - rock band. The front people were guitarist and singer Yiannis Valvis Dionisia Karoki.
After the victory in the Greek preliminary decision they were allowed to compete in Birmingham at the Euro Vision Song Contest 1998. Your rock song Mia Krifi evesthisia ( Eng.: A secret sensitivity) but only reached number 20 of 25 After the contest, the group disbanded.