Kesha and former Van Halen singer Sammy Hagar go way back, so it's no surprise the brash pop star joined the Red Rocker onstage at his Las Vegas residency kickoff Wednesday night. She stormed the ...

Before Van Halen, it was rare to hear the sounds of a hard rock band in most places, unless you were running with a crowd that particularly enjoyed that niche genre of music. But when the Van Halen ...