Funk songstress Chaka Khan and her sister, Yvonne Stevens, have entered into an intensive drug-rehabilitation program to treat their addictions to prescription drugs. The news comes days after Khan unexpectedly pulled out of a scheduled performance at the California State Fair. “Unfortunately, I will miss concert appearances over the summer,†Khan said in a statement to the AP. “However, it’s vital that I put my health and well-being first. I know that I am disappointing some of my fans, but I also know they would want me to recover and be well and healthy.†The Grammy-winner also noted that her addiction involved the same medication that led to Prince’s death, and the Purple One himself — who was a good friend of Khan’s — helped inspire the sisters to seek treatment. “The tragic death of Prince has had us both rethinking and reevaluating our lives and priorities,†she continued. “We knew it was time to take action to save our lives. My sister and I would like to thank everyone for their support, love, and prayers.â€