AFOTBOG (HOB) of course as Richd suggested.
Magdalena (Joglaresa/ Belinda Sykes).
An Excess of Pleasure (Palladian Ensemble)
Julian Bream with Broken Consort - this was my brother's LP, so before 1970, but it certainly got me into early music, that, David Munroe, and a long- lost LP of Terpsichore.
The two early City Waites LPs, the ones they didn't re-issue on CD - Hark the City Waites (?) and A Gorgeous Gallery of Gallant Inventions. I don't know why these were allowed to be forgotten. Perhaps another bulmerism.

But "early music" is nearly as elastic as "folk"- Lucy Skeaping's BBC Radio 3 slot covers from early mediaeval to late 18th century. Which covers about 90% of my interest in "art" music.