I’m recommending this company because I’m astounded by their approach to musical history. Rather than write a 300 page book on American folk music as a while, they’ll write a 300 page book on American folk music from, say, 1920 - 1935 and will include several CDs of material, or maybe field recordings of solo gospel singing from the 20s. It’s the exact sort of specificity I’ve been looking for in music history; where you are informed a great deal about a small section of time, rather than the vague “Well first there was delta blues and then Elvis and then Stevie Ray Vaughan and before you know it Jeff Loomis was sweeping the fuck outta everyone” which many commercially sold music history books have. They are most famous for Goodbye, Babylon: a collection of religious gospel and early folk music from 1900 to 1930~ which I bought a few days back. Just look at it. They’ve got people like Steve Roden writing for them!
Vinyl LPs usually go for $20 and have extensive liner notes. Books go for around $40. Box sets go for around $80.