TUPELO, MISS. -- RCA has released a "new" song by Elvis Presley, a poignant ballad called "My Happiness" that had been believed lost, an RCA executive said in the birthplace of the singer, who died 13 years ago today.

An 18-year-old Elvis recorded the song for his mother, Gladys, on July 18, 1953, at the Memphis (Tenn.) Recording Service. The acetate vanity disc, for which the singer paid $3.98, is thought to be his first recording.

The acetate disc had been in the possession of a high school chum of Presley; RCA obtained the license to the song.

"It could be called the under pinnings of rock-and-roll; it's still blues and country," said Dan Wardell, national director of catalogue music for RCA.

"My Happiness" is the lead cut on RCA's just-released "Elvis: The Great Performances," a companion album to a two-volume music video of the same name due out tomorrow from Buena Vista Video.

Presley recorded another song on the other side of the disc -- "That's When Your Heartaches Begin" -- and discussions about that song are underway at Sun, Wardell said.

However, there is some skepticism about "Heartaches." An expert hired by "NBC Nightly News" said the "aural fingerprints" of a tape of the acetate didn't match a 1956 version of the same song by Elvis.

Wardell said, "The Elvis Presley Estate says it's authentic. We have no reason to doubt it's the real thing."