Music delivered to mobile phones will account for 30 percent of global music sales in 2011, up from 13 percent currently, according to Understanding & Solutions.

The research firm said the increase to 30 percent will amount to $11bn and help offset some of the decline in packaged music revenues.

"Looking to emerging markets, mobile could become the number one platform for music, where packaged CDs haven't gained traction due to piracy and lack of hardware ownership," said Understanding & Solutions Consultant, David Sidebottom.

The study said that Japan, closely followed by the USA, has the most efficient mobile music landscape, although interfaces and software need to continue to improve to make the mobile experience comparable with online.