Elvis not only lives, he sings and he seeks some donations

How’d they do it?

“American Idol” officials weren’t saying much the morning after Wednesday night’s hyped-up duet between Celine Dion and a surprisingly lively looking Elvis Presley for the “Idol Gives Back” fundraising special.

Appearing to appear on stage in a crisp white suit, Presley seemed to interact and harmonize with Dion, in complementary black.

The whole bit had been assembled on videotape previously, so no one in either audience saw Dion, much less had an Elvis sighting, at CBS-TV studios or at Walt Disney Concert Hall, where most of the evening’s live music took place.

Presley’s performance of W. Earl Brown’s “If I Can Dream” came from his 1968 TV comeback special, which rejuvenated his career after it had been in the doldrums for years.

With Photoshop-like technology called Rotorscope, the 39-year-old Presley footage was morphed with recently taped shots featuring 39-year-old Dion, as though it were taking place at the same time as the rest of Wednesday’s show.

An “Idol” spokesman said only that an Elvis impersonator was used “at one point.”

Likewise, there was no announcement detailing when the faux Elvis had left the building.

randy.lewis@latimes.com