Lady Gaga arrived on the pop scene16 years ago, it seemed as if she were going to “Just Dance.”But, while she can still keep up in her platform heels, the 38-year-old superstar has done so much more than that — as both a singer and an actress.Gaga’s new surprise album “Harlequin” — which she just announced on Tuesday before releasing it on Friday — is a companion LP to her movie “Joker: Folie à Deux,” which hits theaters on Oct. 4.
