This is what we found on Wikipedia regarding the Legends In Concert (Las Vegas):

Legends in Concert is a live tribute artist production with shows located primarily in Las Vegas, Nevada; Myrtle Beach, South Carolina; Branson, Missouri; and Waikiki, Hawaii. Legends in Concert features live concerts paying tribute to musical icons of the past and present. The performers resemble and sing like the original artists while being backed by a live band and dancers. Performances are scheduled year round across the globe and its five primary locations in the United States.

The show has been running since its debut at the Imperial Palace on May 5, 1983, the longest running show in Las Vegas history.

It has received entertainment industry awards "Show of the Year", "Entertainers of the Year", "Grand Slam" and "Show of Shows" awarded by the International Press Association.

Each performer looks like the star they portray, and uses their own natural voice to pay homage to their iconic music subject. Legends in Concert live tribute shows are known for their elaborate theatrical sets, magnificent costumes and full array of elaborate special effects, including three dimensional multimedia and multimillion dollar, state-of-the-art lighting and sound systems.