Other artists set to appear include Lionel Richie, Little Big Town, and more.
McKenna's countless achievements include Country Song of the Year Grammys for Little Big Town’s 'Girl Crush,' Tim McGraw’s 'Humble and Kind' and the Highwomen’s 'Crowded Table.'
The event is slated for October 30 at the Frank Irwin Center in Austin, Texas.
Underwood is the most decorated artist in CMT Music Awards history with 23 wins.
The varied history and many interpretations of one of the most enduring John-Taupin compositions.
Thirteen artists in the shortlist are CMT Music Awards nominees for the first time.
Gibb's release finished the chart week with more than twice the combined units of its nearest rival.
Proceeds will go to a global relief fund established by Live Nation for crew members who have lost income due to the COVID pandemic.
The special, hosted by Thomas Rhett and Lauren Akins, will air on November 30 on ABC.
Pardi will honor Joe Diffie while Little Big Town pay tribute to another fallen favorite, Kenny Rogers.
The country group are comprised of Karen Fairchild, Kimberly Schlapman, Phillip Sweet, and Jimi Westbrook and have charted hit singles like 'Pontoon,' 'Girl Crush,' and 'Better Man.'
Little Big Town are serving up another successful single from their 'Nightfall' album, as 'Wine, Beer, Whiskey' climbs the country charts.
Proceeds from the song will benefit the Roots of Music, an organization that empowers the youth of New Orleans.
The show has effectively swapped places with the CMT Music Awards, normally a June fixture but recently moved to 14 October.
Previously announced celebrity guests for the show include Christina Aguilera, Kristin Chenoweth, Little Big Town and Donny Osmond,