A screen at the side of the stage announced "75 years of the oldest independent record company in the world", and a montage of songs released by the UK's most important folk label began with The Man That Waters the Workers' Beer. The remarkable Topic Records deserves a major celebration, and this three-hour festival show in the Oxfordshire countryside almost did it justice.

Folk musicians love anniversaries, and this was also the 50th anniversary of the Towersey festival, and the 39th birthday of a suitably celebratory Eliza Carthy, who – along with her parents, Martin Carthy and Norma Waterson – dominated the proceedings. All three have played a crucial role in the Topic story, and what made this event particularly memorable was the presence of Norma, who has cut back on concerts since serious illness nearly four years ago. She was, she announced, as old as Topic, and though she remained seated she sang magnificently, mixing passion and enthusiasm with an easy, soulful style. Backed by the Gift Band, which included Martin and Eliza, she switched from a stirring treatment of Wayfaring Stranger to exquisite harmony work on the hymn Sleep on Beloved.

The first half was more mixed. There were fine performances by Martin and Eliza, interspersed by appearances from young folk artists reinterpreting songs from the repertoire of celebrated Topic artists. Josienne Clarke and Ben Walker paid tribute to Shirley Collins with The Sweet Primroses, which was pleasant but didn't match Collins' version. The entertaining Jim Causley revived songs by the Copper Family and Peter Bellamy, while Blair Dunlop showed his fine guitar work on Nic Jones songs, and Lau led the singalong on Ewan MacColl's Dirty Old Town.

It was all very entertaining, but the label deserves more. How about a major concert featuring such Topic artists as June Tabor, Linda Thompson, and the great Shirley Collins herself?