I've recently become interested in older forms of music, mostly due to a course I talk about the origins of Brazilian samba and making several friends who are into old-time music. I want to get more deeply immersed in music written before recording technology came about. I'm specifically interested in British dance music written before 1800, rennasiance era folk music, and sea shanties. I have a couple albums from each of these genres, several of them from Folkways, but I'd appreciate suggestions of other labels/artists I can look for who release older music.
R/classicalresources
The compendium there has helped me a lot when I was studying pre-renaissance/medieval compositions.
Also, don't worry too much about particular record labels. Write down a list of composers, head over to your local classical music shop and have at it.
Not your primary interest, but it's worth remembering that there are many hymns written over the last 2000 years and still in popular use. Back to the 1500's is easy - get a hymn-book from a traditional main-line church, and it should have the dates for each tune (usually separately from the words). I imagine you already read music, but YouTube is also useful.
Before the 1500's becomes more difficult because of the changing notation, and the songs are probably less "popular" in nature, so much less likely to be of interest to you, but it's there if you want to get in to things like Byzantine chant.
A huge amount of British music has been collected that dates from before the 20th century. There has been two major revivals - one in the late 19th century, and another in the mid 20th century. Since the 1960's (in particular) there has also been a huge revival of performers playing this style of music.
Do you live in England? In Camden (London) there's a building called Cecil Sharpe House, which is home to a huge library of old folk songs / tunes. There are 2 collectors in particular who are worth looking into - Ralph Vaughan Williams and Francis James Child.
A popular book in the British folk scene is The Penguin Book of English Folk Songs. It contains lyrics and melodies, and was really influential in the 60's revival.
Artists that I would recommend looking into: Nic Jones Ewan Mac Coll, Dick Gaughan, A.L Lloyd,
(These are just a few favourites though - if you're interested I can give you some more names)
With regards to dance music, it's fairly rare to have exact dates the tunes were written - there are lots of collections of music from the last few centuries. There is a huge amount of traditional English dance music, as well as a lively tradition of folk dancing (morris dancing).
John Kirkpatrick is one example of a player of English trad dance music.
(I don't know a huge amount about English dance music - my main interest is Irish dance music - but I grew up around it and am can you give you a fair bit of info if you want)
EDIT: clarity & extra link