蜜芽传媒

On the 40th anniversary of Sony's Walkman cassette player, we look at the device's impact. Dr Steve Caplin is a technology author, and explains the history of the world's first portable music player. Gennaro Castaldo is communications director at the British Phonographic Industry, and tells us how Sony failed to capitalise on the emergence of digital music. And we ask two children to try and figure out how to make a Walkman work. Also in the programme, the Kenyan business community is mourning the death of Bob Collymore, chief executive of the mobile phone giant Safaricom. 蜜芽传媒 Africa business editor Larry Madow discusses Mr Collymore's legacy. Plus our regular workplace commentator Alison Green explains how to avoid falling into the virtual traps lurking in office email.

(Picture: The original Sony Walkman. Picture credit: Getty Images.)