"The Old Ark's a-Movin'", also known as "Grandfather's Tune", "Twin Sisters", "The Two Sisters", "Keep the Ark A-Movin'" (Brody) is an American reel in D Major. The parts are played AB (Phillips) or AABB (Brody). The tune is crooked with 12 measures in the B part. The tune is thought by many to be related to the popular Irish hornpipe "The Boys of Bluehill". Bill Hicks (1972) suggests that the name seems to be derived from the musically unrelated hymn "Keep the Ark a Moverin'." The tune is generally played slower than the normal breakdown tempo. Other American variants (or cognates) go by the names "Pussy and the Baby" (Mel Durham), "She Oughta Been a Lady (Vesta Johnson), "Hell on the Wabash" (Clay Smith of Star City, Indiana)", "Silver Lake" (Samuel Bayard), "Lonesome Katy" (Ira Ford, 1940), "Beaux of Oak Hill" (Elias Howe, Musician's Companion, vol. 3, 1844) and in George P. Knauff's Virginia Reels (1839) as "The Two Sisters". It was printed in Brody's Fiddler's Fakebook (1983) (Keep the Ark a Movin') and Banjo Picker's Fakebook (1985) (Keep the Ark a Movin') and in Phillips's Traditional American Fiddle Tunes, vol. 2 (1995). It was recorded by Taylor Kimble on Blue Ridge Barn Dance (1974) and Carroll County Pioneers (1992), Fuzzy Mountain String Band on Fuzzy Mountain String Band (1972) and A.A. Gray (78 RPM) (1930).