Singer/guitarist MARY KAYE, who is credited with introducing the word "lounge" into Las Vegas shows, has died of heart and respiratory failure. She was 83. Kaye, who had been in declining health, died Saturday (17FEB07) at a Las Vegas hospital. The singer, who was part of the MARY KAYE TRIO, was the one who suggested building a stage in the bar area of the Last Frontier hotel and calling it a lounge. The group performed in the early hours of the morning, helping to turn Las Vegas into a 24-hour entertainment capital. Headliners such as Frank Sinatra and ELVIS caught the trio's act between 1-6 am. The best-known version of the trio included Mary Kaye on guitar, her older brother NORMAN on bass and FRANK ROSS, the group's comedian and sometimes accordionist. The band released dozens of albums before breaking up in 1966.