On Thursday, July 16, at 5:00 PM, at the Park Venue, two Greek groups will be featured. Panos Liaropoulos and the Greek Music Ensemble, which he directs and will include other highly talented local musicians, will be playing a variety of Greek music. Appearing with them will be the Boston Lykeion Ellinidon dance troupe. Accompanied by live Greek music, the troupe will be authentically attired in regional dress and display dances from several areas of Greece.