As a point of background information I will mention that I am a retired commercial photographer, so I have followed copyright evolution for several decades. I am not a copyright expert, and my primary knowledge is of copyright as it relates to images, not music. However, copyright practice across various media needs to be logically consistent to be effective, so practice in one area will influence others.
ghmerrill wrote:
It was recognized that as a practical matter buyers would need, and were permitted, to immediately create backup copies to protect against disc failure or file corruption.
When you say "It was recognized ... and were permitted ...", is this a matter now of copyright law -- so that it covers ALL cases of copying for such uses? -- or is this an explicit right that a particular publisher may grant to the purchaser (and hence some publishers may grant it and some not)?
I believe this began as a market force, not a copyright issue. Sometime in the 90's (perhaps earlier) software customers demanded assurance that they would not lose their investment due to unstable software or computers, and suppliers complied to avoid loss of sales or market share.
However, common practice is one of the ways that copyright practice evolves. Due to previous common industry practice — and the lobbying that goes with it — there are references to legitimate copying of software to protect against loss of originals in the Digital Copyright Millennium Act of 1998.
As to your specific question — "is this a matter now of copyright law -- so that it covers ALL cases of copying for such uses?" — I would say no. The issue of copying sheet music we are discussing would be, if it were to be decided in a court, a fair use issue; similar accepted practice in a different area could be a guide but perhaps not a determinant.
Here is what the statute says about fair use:
In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include—
(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
(2) the nature of the copyrighted work;
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
(4) the effect of the use upon the potential market for or value of the copyrighted work.
You can see from the above that ultimately a lot of subjective thinking goes into applying these four points. Practice and case law have helped to crystalize these factors but there will always be new situations that fall into grey areas.
When you hear the real experts talking about this they always hedge when asked about a new issue.
Hup