The second in this lavishly-illustrated music series tells the epoch-changing story of what happened when the voice of Bing Crosby met the trumpet of Louis Armstrong. Until then singers had just been part of the jazz big bands, not stars in their own right. All that changed with the emergence of Bing Crosby as the first true pop star of the recording era and it wasn't long before Frank Sinatra was generating the kind of fan hysteria today's boy bands would die for. Both acknowledged a huge debt to Louis Armstrong, whose own hip and freewheeling singing style also paved the way for singers like Billie Holiday and Ella Fitzgerald. From now on it was singers who would quite literally call the tune, changing popular song and the music business for ever.