Well I have to say it is more than that. The revolution of music started longer than any of can remember. We all have a favorite singer. Rock and Roll, Country, Classical, Jazz, Rhythm and Blues, when we hear our song it either mellows us or it excites us. You want to know why don’t you? Well it has to do with the tone, the (frequency range). The year 1955 is the year that The International Standardization Organization made 440 Hz a tuning standard for music pitch. Before that it was 432Hz.
As your question why the change to a higher frequency? I will leave it at this, watch the videos, I think we all are smart enough to understand what has happened and how we can somehow get a bit of our life back. Also check out the last link, it really explains what happened and how it happened. Would it be nice to change the world, by the way we hear it.
Cymatics – Bringing Matter To Life With Sound
6 Secrets “They” Don’t Want You to Know