Apple is working hard to shore up its share of the Japanese digital music market.

The company faces strong challenges there, not least from Sony, where it competes against that company on the its home ground. The main obstacle to iTunes in Japan is the popularity of mobile phone music services there.

Now Apple is kicking back - offering free song downloads at music festivals in Japan. That move is designed to increase its iTunes sales, which hold just 5 per cent of Japan's market, in stark contrast to the company's leading poisition outside that country.

Apple's main focus is to convince Japanese consumers to abandon mobile phone download services in favour of computer-based systems, such as iTunes.

"Apple's strategy might be paying off," Reuters reports. Internet song download sales to computers surged 457 per cent in the first half of 2006, while mobile phone downloads grew just 160 per cent.

Apple's iPods may also help the company build iTunes Japan's market share - iPods dominate the top ten list of digital music players sold in the country. Sony's Walkman-brand E-series player is a tenth-place contender.