The basic MP3 decoding and encoding technology is patent-free in the European Union, all patents having expired there. In the United States, the technology will be substantially patent-free on 31 December 2017 (see below). The majority of MP3 patents expired in the US between 2007 and 2015.
When will the technology be patent - free in the United States?
31 December 2017

In 1687, Isaac Newton published the Principia Mathematica, detailing two comprehensive and successful physical theories: Newton's laws of motion, which led to classical mechanics; and Newton's Law of Gravitation, which describes the fundamental force of gravity. The behavior of electricity and magnetism was studied by Faraday, Ohm, and others during the early 19th century. These studies led to the unification of the two phenomena into a single theory of electromagnetism, by James Clerk Maxwell (known as Maxwell's equations).
What concept did the Law of Gravitation deal with?
the fundamental force of gravity

The Times Literary Supplement (TLS) first appeared in 1902 as a supplement to The Times, becoming a separately paid-for weekly literature and society magazine in 1914. The Times and the TLS have continued to be co-owned, and as of 2012 the TLS is also published by News International and cooperates closely with The Times, with its online version hosted on The Times website, and its editorial offices based in Times House, Pennington Street, London.
In 1914, a separately paid-for supplement for The Times was a magazine that featured what kind of content?
weekly literature