** 1/2 Vanessa Daou, “Zipless,” Krasnow Entertainment/MCA. Frank female sexual imagery didn’t start with Liz Phair. Erica Jong’s erotic poetry has for a good generation set a standard. Daou and her producer-husband Peter here slip 10 Jong poems between sensuous sheets of silky bass and keyboards and breathy vocals, with the author herself speaking one number. The atmospheres are a bit forced at times, but effective.