Viv Albertine posted her tribute to Ari Up on her blog
the whole thing is really great. here's an excerpt:
She was totally unselfconscious about her body and remained so throughout her life. Ari's biggest gift to me was she made The Slits a safe place for a woman of any shape or size to be relaxed and free with her body. She celebrated womanliness, she reveled in it. She was so sensual on and off stage it was empowering to any girl who saw her. I'm not kidding. The way she carried herself was a revolution.
Stage was Ari's home. She was in her element there. That is where she could let go completely. She was at her best there. She pissed there. Stage is one of the only places a woman with that much energy, power and self belief can show off and sometimes get away with it.
The singing voice that Ari developed, that has been so copied and referenced over the years came very quickly. That is because she was true to herself. She used sounds that she heard around her from animals, birds, playground chants, accents and melded them all together. It happened without thinking. She was as unselfconscious about her voice as she was about her body.