[1][2] The label name was crafted by Rosenthal to suggest a combination of the Greek oracle, nearby Adelphi, Maryland, as well as a tip of the hat to a John Fahey song, "The Downfall of the Adelphi Rolling Grist Mill".
In the mid-1970s, two of Adelphi's biggest selling artists were the Nighthawks and the Rosslyn Mountain Boys.
Musician signings continued into the 1990s and, after a short hiatus, resumed in the 2000s with studio sessions in New Orleans by Ken Swartz & The Palace of Sin, and in Silver Spring, Maryland sessions with the Rose Sheehan Group including vocals by Lisa Null.
Musicians on that label are (among others) The Nighthawks, Catfish Hodge and Roy Buchanan,[3] (rock); Lenny Breau,[4] Reuben Brown and Richie Cole (jazz);[4] Yellowman, Big Youth and Toots & the Maytals (reggae); Rev.
Robert Wilkins (blues and spirituals); plus Nathan Beauregard, Roy Book Binder, Roy Buchanan, R. L. Burnside,[6] Gus Cannon,[6] David Honeyboy Edwards, Paul Geremia, Mississippi John Hurt, Backwards Sam Firk, Richard "Hacksaw" Harney,[7] Skip James, Furry Lewis,[6] Bill Blue, Little Brother Montgomery,[6] Charles Tyler[5] and Bukka White (blues), plus Patrick Sky (folk).