Why was Ernest Ansermet’s 1946 recording of Stravinsky’s Petrushka important for high-fidelity recording?

Ernest Ansermet’s 1946 recording of Igor Stravinsky’s Petrushka was a landmark moment for high-fidelity audio because it utilized British Decca’s innovative ffrr (full frequency range recording) process.1

By dramatically extending the frequency range of discs, this recording provided a level of sonic clarity and detail that had not been previously achieved. It served to awaken many record collectors to the future possibilities of high-fidelity, or "hi-fi," sound reproduction on the phonograph, setting a new standard for the industry in the post-World War II era.1