Tim McGraw concert tickets and an autographed Florida Georgia Line poster are amongst items country fans may be interested in when the Music for Newtown auction begins on March 25. Additionally, the Avett Brothers and Thomas Rhett have donated items to benefit the families of victims and first responders from the December tragedy at Sandy Hook Elementary School in Newtown, Conn.

The most coveted item still promises to be the electric guitar with Taylor Swift's autograph, but McGraw concert tickets for his June 30 show in Holmdel, N.J. are sure to draw significant attention. Rhett has offered an autographed copy of his acoustic EP, and the Avett Brothers have donated an autographed vinyl copy of their most recent album 'The Carpenter.'

Non-country artists supporting the auction include the Eagles, Colbie Caillat, Jack Johnson and Gotye. Four tickets to a May taping of 'The Voice' are up for auction as well. The bidding begins at 3PM ET on March 25 and lasts until 3PM ET on March 27. One hundred percent of the proceeds go to the Sandy Hook School Support Fund. Republic Records is the sponsor of the online auction.