Miranda Lambert surprised a crowd in Nashville on Wednesday when she made her first public appearance following the announcement of her divorce from Blake Shelton.
Lambert, who released a joint statement with Shelton on Monday that they were calling it quits after four years of marriage, showed no signs of sadness at her BFF Ashley Monroe's show, sporting a wide smile and looking stunning – sans rings – in a black summer dress and studded boots.
The country star, 31, took the stage with Monroe, 28, at The Basement in East Nashville to sing "Heart Like Mine," a song they co-wrote with Travis Howard.
After guest performances from country duo Striking Matches, Jessi Alexander and album co-producer Vince Gill, Monroe came back on stage for an encore and introduced "one of my best friends, Miranda Lambert!"
The crowd erupted with cheers.
"I'll take the high harmony," quipped the six-time ACM Female Vocalist of the Year.
The show, Ashley Monroe & Friends, was a live performance of songs from Monroe's new album, The Blade, for the SiriusXM program The Highway.
The star-studded crowd included Natalie Stovall, Little Big Town's Phillip Sweet and his wife Rebecca, as well as Nashville star Sam Palladio with girlfriend (and ex on-screen squeeze!) Chaley Rose, among others.
Monroe's new record will be released Friday.
For more on why Shelton and Lambert decided to end their marriage, pick up the latest issue of PEOPLE, on newsstands Friday
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