always change and change again interview by SABINE HELLER portrait in her Paris apartment by GIASCO BERTOLI 1960s sex kitten. Mick Jagger’s girlfriend. Homeless heroin junkie. For the last 50 years, Marianne Faithfull has lived a life as varied as the labels that have defined her. But today, as the iconic singer- songwriter-actress releases her 50th-anniversary album, starts a world tour, and publishes a new book about her life, it is Marianne — defiant, self-possessed, candid, and yet vulnerable — defining her- self on her own terms. A far cry from the silenced, naked woman wrapped in a fur rug you might remember, Marianne expresses her- self freely — and with real strength and sensitivity. SABINE HELLER — Who is Marianne Faithfull today? MARIANNE FAITHFULL — I’m very connected to all the different periods and times I’ve ever been through, but I always change, and change again. For instance,…