Mr. Davis then left advertising and recorded an album of New Age music under the name Mannheim Steamroller.

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When the bowl-playing stopped and the recorded New Age music commenced, the intensity waned and it suddenly felt like we were customers at a spa where the masseuse forgot to show up.

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On the rare occasions I've visited spas, I'd gone for the full-meal deal massage, sauna, swimming pool, piped-in new-age music.

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Mr. Davis's New-Age-meets-classical Christmas-music ensemble, now made up of two large bands who crisscross the country during the holidays, has sold more than 28 million Christmas records.

WSJ: The Mannheim Steamroller Founder's Wild Holiday Home

Their music has encompassed genres ranging from heavy metal to new age.

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Apps like Tonara are now bringing sheet music into the digital age, as well as leveraging new technologies (polyphonic score following) to provide a truly interactive experience to musical scores.

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But of the three rock stars who died at the start of the 1970s, it is Jimi Hendrix whose music became the most potent shorthand for the new youth culture of the age.

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In 1973, Aimard won first prize at the Messiaen Competition, and at age 19 he was chosen by Pierre Boulez to become the first solo pianist for the influential new music group, Ensemble InterContemporain.

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