Demjén Ferenc "Rózsi" is the correct artist name. He was the founder of the Hungarian "Számum" band. Later he went to the "Dogs" band after he was the member of the Liversing. in1968 he was the singer of the Meteor (Hungarian) band, in 1969 he was the singer Radics Béla's band Sakk-Matt. In 1970 he was the member of Tűzkerék. Read more on Last.fm