Nate Adams
The little known Nate Adams recorded his only 45 in Atlanta, GA under the supervision of that talented music man Johnny Brantley. 
Why Is It Taking So Long is a good song sung well and arranged really well, especially the horns which sound so good. Adams really gets to grips with it, helped by a strong female chorus. Brantley cut Tony Baxter on the same backing track.
UPDATE ~ Mike Cassidy has kindly written with a link to more info on Nate Adams on Colin Dilnott's excellent blog "In Dangerous Rhythm". Colin mentions three unissued cuts from the session - "Yes You Did", "A Fool For You" and "Sophisticated Alabama Soup Bone". In addition to the version of "Why" by Tony Baxter, Colin also mentions a version using the same backing track by Geroge Scott from his desperately rare LP on Maple, also produced by Brantley. A reader at Colin's blog called Sakai has left a comment which states:-
"I am writing a book for a friend, John Harley. John and Nate were in the Air Force together, and they both sang with an Air Force group by the name of the Montclairs. When they were discharged, they formed a duet. They won a contest and the grand prize was a recording contract with Lieber and Stoller. Lieber and Stoller sent Johnny Brantley to represent them. He signed them up under his management. They only made one recording for Lieber and Stoller, "Keep it Up," and "I Got a Dream" on the flip side. They later went with Redfield Productions, but left the company over mismanagement. Redfield had named them "Soul Brothers" and when they left, they could no longer sing together under that name. For awhile they sang under the name of George & Sonny Sands. I am assuming that after they broke up, that Nate began singing for Johnny Brantley Productions."
The recording that Sakai mentions for Leiber & Stoller as the Soul Brothers was iisued as Blue Cat 107 in 1965. Sadly neither side is great soul.
You can find more of Colin;s research into Adams' work here.
I'm grateful to Mike Cassidy for spotting this info.