It’s just like in the movies – the male performers dress up as well-known female singers and lip-sync to the hits.
From Ms Wiki: “American drag queen RuPaul once said “I do not impersonate females! How many women do you know who wear seven-inch heels, four-foot wigs, and skintight dresses?” He also said, “I don’t dress like a woman; I dress like a drag queen!”.”