The cell phone industry <A HREF="http://news.zdnet.com/2100-1035_22-6159218.html?tag=nl.r23660">must improve the mobile music experience</A> for consumers or risk losing out to new competitors like Apple, Warner Music Group's CEO warned Wednesday at the 3GSM World Congress. Edgar Bronfman Jr. said in a keynote speech here that although there are already millions of music phones available throughout the world, only about 8.8 percent of people with the devices actually buy their music over the air. The reason, he said, is because such purchases are expensive, complicated and slow.