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While the fundraising results of Blake Shelton and NBC's efforts to raise funds for Oklahoma following the May 20 tornado remain to be seen, the overnight TV ratings show plenty of promise. According to Nielsen, Wednesday's Healing in the Heartland: Relief Benefit Concert, which was organized in just a few days, topped viewership for the night with 8.6 million viewers on NBC. It was the network's highest-rated program in its time slot since November 7, 2012.

The fundraising event featured Shelton and fellow The Voice judge Usher, in addition to Miranda Lambert, Reba McEntire, Vince Gill, Luke Bryan, Rascal Flatts, Darius Rucker and Ryan Tedder of OneRepublic. Jimmy Fallon, Carrie Underwood, Garth Brooks, Trisha Yearwood, Alicia Keys and Toby Keith also made video appearances throughout the program.

As with all live programming, final numbers will likely adjust upward. It's also worth noting that multiple networks—including Style, CMT, G4, Bravo, E! and Palladia—and online platforms streamed the concert live. Many of those channels do not typically release viewership tallies.

NBC's benefit concert for Hurricane Sandy last year raised about $50 million. Donation results following Wednesday's event likely won't be known for some time.