This case was subsequently eclipsed by Congress's intervention in the form of an amendment to the Copyright Act of 1909, introducing a compulsory license for the manufacture and distribution of such "mechanical" embodiments of musical works.

In the early 1980s the issue was in considerable doubt, and initially several lower court decisions held that object code was not a "copy" of a computer program.

[3] They upheld the protectability of object code embodiments of computer programs and rejected the supposed requirement that a candidate for status as a work of authorship must communicate a message to human readers or perceivers.

In principle, what infringes could be broader than what gives rise to copyright, on the theory that works of authorship need a hedge or moat around them to assure adequate protection.

As explained in greater detail in the Wikipedia article Piano Roll Blues, the legal fiction developed in US patent law that placing a new program in an old general-purpose digital computer creates a new computer and thus a "new machine" for purposes of section 101[4] of the US patent statute (listing patent-eligible subject matter).