Celtica started as a traditional session band in the St. Louis Metro East area. The group first formed in 2006 as the sessions grew in size. Paul Niesen, the group leader, has taken the band from its early days in a pub called Castletown Geoghegon in Belleville to engagements with the Belleville Philharmonic Society and the Great Rivers Choral Society.
"Belleville Sessions" is a collection of the band's favorite and most-requested songs and traditional as well as original tunes. The group tries to include a wide variety of Celtic music, including music from Capt Breton, the Brittany Coast, and Galicia. The music touches the heart and soul.
Celtica draws its influences from several performing groups, including Cherish the Ladies, Gaelic Storm, the Chieftains, Danu, Natalie MacMaster, and Stonecircle.