From 1970 through 1975, then from 1985 through present, Irish folk group Tír na nÓg especially performed concerts in the United Kingdom, either as a support act to bands and solo artists like Jethro Tull, Steeleye Span, Supertramp, Elton John, Hawkwind or as main performers.
1970
Jethro Tull tour. Support bands were Procol Harum and Tír na nÓg
References
Tír na nÓg concerts Wikipedia(Text) CC BY-SA