You can do research on "historically informed performance." I don't know if there are particular labels that specialize in this, certain performers, such as the conductors Nikolaus Hanoncourt, Trevor Pinnock, Phillippe Herreweghe, Christopher Hogwood, and John Eliot Gardiner are popular practitioners.
There is another performer/composer that is particularly interesting and unique that I personally think is worth looking into--Jordi Savall. He is a student of early music (medieval, renaissance and baroque) and a student of musical practices from a wide range of cultures (European, middle east, african) and has made some amazing recordings that include his own original compositions based on different periods and locales. This is, not strictly speaking "authentic," but his music is based on his research and is so compelling I say "so what?"