That it was written by someone under the employment of Shazam makes it likely that it describes their algorithm, but for patent protection, what matters is that you can’t apply for a patent for an invention that has been published.
https://www.science.org/content/article/patent-first-publish...: “According to U.S. law, a patent cannot be obtained if an invention was previously known or used by other people in the U.S., or was already patented or published anywhere in the world. Furthermore, publicly using or selling an invention more than 1 year prior to filing a patent application completely bars you from ever winning a patent on that invention.
[…]
In Europe, for instance, there is no 1-year grace period--the chances of winning patent protection is lost the instant an invention becomes public”
https://www.science.org/content/article/patent-first-publish...: “According to U.S. law, a patent cannot be obtained if an invention was previously known or used by other people in the U.S., or was already patented or published anywhere in the world. Furthermore, publicly using or selling an invention more than 1 year prior to filing a patent application completely bars you from ever winning a patent on that invention.
[…]
In Europe, for instance, there is no 1-year grace period--the chances of winning patent protection is lost the instant an invention becomes public”