Well, I think I've tracked down Mr. NB Chisholm of Woodridge [rather than "Wardbridge"], Virginia. Woodridge is in Albemarle County, south of Charlottesville, here:

http://maps.google.com/maps/place?client=safari&rls=en-us&oe=UTF-8&um=1&ie=UTF-8&q=Woodridge+VA&fb=1&gl=us&ftid=0x89b39036bd34dd

Here is the family information on Mr. Chisholm. Would you believe that his name was "Napoleon Bonaparte Chisholm"!

http://www.kalelrojin.com/ancestry/pace/desc12.htm#5

and here, which mentions Sharp's visit, but forgets his name!

http://www.kalelrojin.com/ancestry/pace/not12.htm#5

and here is a picture of his wife

http://www.kalelrojin.com/ancestry/pace/images/sbd.htm

He was a brother of James Chisholm, who was married to Emma Truslow of Nellysford, VA. Sharp also collected some songs from them in Nellysford. Nellysford is also the home of John Minear.

Cecil Sharp says in his introduction to ENGLISH FOLK SONGS IN THE SOUTHERN APPALACHIANS, p. xxviii, that he collected 24 songs from NB Chisholm. I have managed to find nine ballads and four songs in Sharp's collection that he attributes to NB Chisholm.

Here are the ballads. They are given with : "Title" Child-number, Sharp's number and variant, page in Sharp's ENGLISH FOLK SONGS IN THE SOUTHERN APPALACHIANS, and Volume number, page number, and variant number in Bronson's THE TRADITIONAL TUNES OF THE CHILD BALLADS.

"Sir Lionel" C-18, Sharp No 9 B, p. 54 in EFSSA; and Vol I, on page 273, "15" in Bronson.
"The Cruel Mother" C-20, Sharp No 10 D, pp. 56-57; and Vol I, on p. 292, "44" in Bronson.
"Fair Margaret & Sweet William" C-74, Sharp No 20 G, pp. 139-140; and in Vol II, on p.181, "59" in Bronson.
"Barbara Allen" C-84, Sharp No 24 H, p. 191; and Vol II, p. 387, "184" in Bronson.
"The Maid Freed From the Gallows" C-95, Sharp No 28 D, pp. 2110-211; and Vol II, p. 465, "42" in Bronson.
"The Gypsy Laddie" C-200, Sharp No 33 G, p. 237; and Vol III, p. 215, "33" in Bronson.
"Wife Wrapt In Wether's Skin" C-227, Sharp No 39 A, p. 271; and Vol. IV, p. 161, "38" in Bronson.
"The Farmer's Curst Wife" C-278, Sharp No 40 B, pp.276-277; and Vol IV, p. 202, "54" in Bronson.
"The Brown Girl" C-259, Sharp No 44 E, p. 297; and Vol IV, p. 419, "42" in Bronson.

And here are the four songs that I could find. This leaves eleven songs unaccounted for, but they are probably in Sharp's unpublished manuscripts.

"The Keys of Heaven" Sharp No 92 C, pp. 47-48.
"The False Young Man" Sharp No 94 E, p. 55.
"My Mother Bid Me" Sharp No 108 A, pp. 93-94.
"The Frog In the Well" Sharp No 221 A, p. 320.