Is it permissible to make digital copies of choral music that is legally owned by the institution to students in choral and instrumental ensembles? Some students may be studying remotely and mailing physical copies may result in lost or non-returned copies.
There are four ways it can be permissible:
1. Check the license from the publisher and see if the purchase of the physical copies came with any digitization/duplication permission. You'd be surprised how many rights you buy (or don't buy) when you make that hard copy purchase. Publishers take a variety of approaches on this, and an individual publisher's permissions may change from work-to-work, so confirm (or rule out) this approach for each work.
2. If the license does not allow making digital copies, contact the publisher, and see if it can be expanded. Publishers are now getting many requests like this and may be ready with a simple (and affordable) solution.
3. I am not a fan of them (they are as outdated and as risky as the Ford Pinto), but the "CONTU" guidelines speak to this issue. I am including the relevant guidelines, as presented in Copyright Office Circular 21, under this answer. If one of your precise needs fits one of the "permissible uses" listed in Circular 21, you are all set.
4. Speaking of CONTU, the first "permissible use" listed in the guidelines may help you out here, with a slight twist on your scenario. In the event that the physical copies listed in the question are mailed out and not returned as feared, the guidelines allow for emergency copying after the fact (of course, they also require that at some point, you purchase more physical copies, but at least you can get the copies to the students).
Those are my four solutions, based on conventional approaches and current case law.
I'll also throw out a "fifth option" based on a slightly different approach, which, depending on some precise facts, could work for faculty teaching choral classes:
The 110 Solution
Copyright Section 110 allows an academic choral group (if meeting as part of a class) to display "a work in an amount comparable to that which is typically displayed in the course of a live classroom session," during an online class/rehearsal.
How can that help with the member's scenario?
If the class was still meeting physically, Copyright Section 110(a) would allow us to perform the song and to display the music on the in-class smart board. In the online environment, the same performance and display could happen via the internet, as allowed by 110(b) (the "TEACH Act")—again, so long as only the amount "typically" displayed in class was shown.
Whether in-person or online, the rehearsal would include review of the different parts for bass, tenor, alto and soprano, with the relevant music displayed on the screen. While an academic institution can't tell people to take screen shots of the music displayed for rehearsal purposes, students who want to snap screenshots of a class to take notes is a fact of modern-day academia. If a student who was told to purchase a copy of their part uses this method to ensure they are practicing on an incremental basis, that's out of the school's control, and the student can make their own claim to fair use.
This type of solution should never be used as a deliberate alternative to the purchase of individual copies. But so long as the display is incremental and truly a part of the in-class experience, it is a viable option.
I wish all music faculty approaching the Fall 2020 semester many good performances, whether virtual, or face-to-face. These are tough days for people who love to sing, who enjoy the community of a choir, and who need to hone their vocal art in collaboration with others. Hunting for music should not add to the burden, and with a few tricks and an awareness of the limits of the law, it doesn't have to.
Guidelines for Educational Uses of Music
The purpose of the following guidelines is to state the minimum and not the maximum standards of educational fair use under Section 107 of H.R. 2223.
The parties agree that the conditions determining the extent of permissible copying for educational purposes may change in the future; that certain types of copying permitted under these guidelines may not be permissible in the future, and conversely that in the future other types of copying not permitted under these guidelines may be permissible under revised guidelines.
Moreover, the following statement of guidelines is not intended to limit the types of copying permitted under the standards of fair use under judicial decision and which are stated in Section 107 of the Copyright Revision Bill. There may be instances in which copying which does not fall within the guidelines stated below may nonetheless be permitted under the criteria of fair use.
Reproduction of Copyrighted Works
1 Emergency copying to replace purchased copies which for any reason are not available for an imminent performance provided purchased replacement copies shall be substituted in due course.
2 For academic purposes other than performance, single or multiple copies of excerpts of works may be made, provided that the excerpts do not comprise a part of the whole which would constitute a performable unit such as a section¹, movement or aria, but in no case more than 10 percent of the whole work. The number of copies shall not exceed one copy per pupil.
3 Printed copies which have been purchased may be edited or simplified provided that the fundamental character of the work is not distorted or the lyrics, if any, altered or lyrics added if none exist.
4 A single copy of recordings of performances by students may be made for evaluation or rehearsal purposes and may be retained by the educational institution or individual teacher.
5 A single copy of a sound recording (such as a tape, disc, or cassette) of copyrighted music may be made from sound recordings owned by an educational institution or an individual teacher for the purpose of constructing aural exercises or examinations and may be retained by the educational institution or individual teacher. (This pertains only to the copyright of the music itself and not to any copyright which may exist in the sound recording.)
1 Copying to create or replace or substitute for anthologies, compilations or collective works.
2 Copying of or from works intended to be “consumable” in the course of study or of teaching such as workbooks, exercises, standardized tests and answer sheets and like material.
3 Copying for the purpose of performance, except as in A(1) above.
4 Copying for the purpose of substituting for the purchase of music, except as in A(1) and A(2) above.
5 Copying without inclusion of the copyright notice which appears on the printed copy. (iv)
Discussion of Guidelines
The Committee appreciates and commends the efforts and the cooperative and reasonable spirit of the parties who achieved the agreed guidelines on books and periodicals and on music. Representatives of the American Association of University Professors and of the Association of American Law Schools have written to the Committee strongly criticizing the guidelines, particularly with respect to multiple copying, as being too restrictive with respect to classroom situations at the university and graduate level. However, the Committee notes that the Ad Hoc group did include representatives of higher education, that the stated “purpose of the … guidelines is to state the minimum and not the maximum standards of educational fair use” and that the agreement acknowledges “there may be instances in which copying which does not fall within the guidelines … may nonetheless be permitted under the criteria of fair use.” The Committee believes the guidelines are a reasonable interpretation of the minimum standards of fair use. Teachers will know that copying within the guidelines is fair use. Thus, the guidelines serve the purpose of fulfilling the need for greater certainty and protection for teachers. The Committee expresses the hope that if there are areas where standards other than these guidelines may be appropriate, the parties will continue their efforts to provide additional specific guidelines in the same spirit of good will and give and take that has marked the discussion of this subject in recent months
 Checking a license is not an exact science. Some publisher's use a catch-all that is included on their invoices. Others put the information right on the music. Others like to make you really hunt for it, but it is usually part of the sale transaction. This is why, when making a purchase of music, it is good to take a screen shot or save the paperwork related to the purchase.
 Note: To my knowledge this work does not exist, but it is on my wish list of music to hear. I love it when genres collide.
 This new version would be a "derivative work" based on the original, and have its own copyright protection as a musical composition.
 We have reached the limit of my choral knowledge. Is there separate sheet music for mezzo-soprano and counter-tenor? Probably. I am sorry, I quit choir in 7th grade.
We were discussing the Rule of 5 of copyright laws and wondered if it was limited by a single location or an institution. For example, if a public library has multiple branches can one branch request 5 articles from a single year from a journal and then another branch also requests articles from that same journal and year? Or did the first branch already use the maximum number of copies?
What about universities or hospital systems with multiple campuses and libraries? Thank you!
Libraryworld: a place where people gather to discuss information, and the best ways to share it with their community. A place where people are just as likely to discuss the "Rule of Five" as the "Rule of Three." A place where routine conversation tackles everything from new database technology, to guidelines from the now-obscure "National Commission on New Technological Uses of Copyrighted Works" (CONTU).
But since not everyone in Libraryworld knows about "The Rule of Five," let's give some background.
The "Rule of Five" pertains to guidelines for applying a very small section of 17. U.S.C 108, the law giving libraries and archives special exemptions from copyright infringement.
That's right, Section 108 of the Copyright Act sets out important exemptions from infringement for libraries and archives who are open to the public. But since the copyright law giveth and the copyright law taketh away, this "very small section" of the law, sub-section (g)(2), cancels those exemptions if a library or archives using them:
… engages in the systematic reproduction or distribution of single or multiple copies…of material described in subsection (d)…. [emphasis added]
"Sub-section (d)" creates:
[The right to make and distribute] a copy, made from the collection of a library or archives where the user makes his or her request or from that of another library or archives, of no more than one article or other contribution to a copyrighted collection or periodical issue…[emphasis added]
Aha, the right to make copies of "articles" and "contributions to collections!” Yes, 108 sub-section (d) lets you make those…either for patrons at your own library, patrons at another library, or a requesting institution. That's a very big, and very important exception to infringement. It is one of the cornerstones of inter-library loan collaboration.
But how does (g)(2) limit this important right? By prohibiting "systematic reproduction or distribution" of the content. And what does "systematic reproduction or distribution" mean?
The law doesn't say. And since Section 108 was adopted in 1976, it still hasn't said.
That's where "CONTU" stepped in.
Convened in 1977, CONTU was the "National Commission on New Technological Uses of Copyrighted Works." In 1978, it issued "Guidelines" that attempted to provide clarity about the meaning of "systematic reproduction or distribution."
This is what they came up with:
[F]illed requests of a library or archives (a “requesting entity”) within any calendar year for a total of six or more copies of an article or articles published in such periodical within five years prior to the date of the request.
This limitation is called the "Rule of Five," since the requesting entity is limited to five copies of content less than five years old, from the same source. 
CONTU tried to give libraries a precise mathematical formula and documentation system for abiding within the protections of 108. While such a precise formula can be useful, I find it more helpful to think of the "Rule of Five" in the context of another part of Section 108 (g)(2):
That nothing in this clause prevents a library or archives from participating in interlibrary arrangements that do not have, as their purpose or effect, that the library or archives receiving such copies or phonorecords for distribution does so in such aggregate quantities as to substitute for a subscription to or purchase of such work.
In other words: libraries shouldn't use 108 as a replacement for budgeting to purchase a critical magazine or journal needed at a specific location. They shouldn't collude between institutions to strategically subscribe and then share journals to the detriment of the publisher. BUT at the same time, when a spontaneous need arises within your area of service, and you have that magazine or journal, don't hesitate to use your network to provide a 108-sanctioned copy. But once the same place calls you five times in a year about the same source, say "Okay…time for you to get your own subscription."
Although I did not find it in the CONTU/108 commentary, I believe this approach reveals why CONTU's limit on copies is calculated based on the requests of the "requesting entity," and not fulfillments by the lending source. Just think of it this way: a library or archives should not hesitate to use 108 to fulfill its mission information access. However, it should take equally great care to show it isn't using 108 to help another library, or a patron, avoid a subscription fee. By limiting copies from a single source given to another entity to five, CONTU tried to do just that.
Okay, there's some 10,000-foot background on the "Rule of Five." Now let's focus on the member's two questions:
1. [I]f a public library has multiple branches; can one branch request 5 articles from a single year from a journal and then another branch also requests articles from that same journal and year? Or did the first branch already use the maximum number of copies?
2. What about universities or hospital systems with multiple campuses and libraries?
Let's take a close look at these questions. In both scenarios, the requested articles are not going to a separate entity (or as 108 and the CONTU guidelines call it, a "requesting entity); rather, the copies are going to branches of the same entity: a branch of a library, a part of a university campus, or a part of a hospital entity.
Because the copies are going to the same entity, as I see it--and insofar as actual authorities like congressional commentary, the Copyright Office, and the courts can guide me--the CONTU Guidelines do not apply to the member's scenarios. Rather, the limit of a single institution's ability to make copies for itself is defined by the (g)(2)'s more thematic bar on activities that "substitute for a subscription to or purchase of such a work," and of course, the rules of fair use.
How does this play out? Applying our 108/CONTU background: if a hospital whose library is open to other hospitals has five library suites in different buildings, and wants to put a copy in each suite, it should not apply the "Rule of Five." In fact, this type of example (except they used branch libraries) is cited by the Copyright Office's guidance as exactly not the type of activity 108 was intended to protect! Rather, the hospital would do a "fair use" analysis, or use another part of 108, to make the copies it needs. Or, if there is no other way, would not make them at all.
Now, with all that said, it is important to note that the entity can make 108/CONTU copies for other "requesting entities" (users, other libraries)…so long as the other 108 criteria applies. For instance, 108 allows me, and even up to 10 other people (or 20, or 30) to visit your library and make a copy of an article, so long as we are not part of a discernable, coordinated "scheme" like a faculty member sending all their students in to copy the same content. Because of this, 108 is a powerful tool for information access. And it's been that way since 1976.
Now, let's stop playing around in the 1970's, and discuss some modern features of this type of "multi-branch" dilemma.
The fact of the matter is, unless the library/university/hospital is purchasing physical copies, at this point in 2020, what might be more relevant than CONTU's "Rule of Five" is the terms of the license from the subscription service the library gains access to the copies through. Remember, as a general rule, exemptions to copyright infringement do not trump violations of valid negotiated contract terms. So, if a library gains access to the content through a license that limits the number of copies, it might be that the specific "Terms and Conditions"--not the CONTU Guidelines or basic copyright law--that apply.
This is why careful review of all licenses held by libraries grows more critical, year after year. It is also why whenever possible, I advise that every license for content should have a clause expressly stating that the terms of the license do not limit the library's rights under Copyright Law Section 107, 108, and 110, and the ADA.
So, where does that leave us on the "Rule of Five?"
There's a brassy phrase people can use to reply when asked "How are you?"
"Five by five," they might say, taking a verbal saunter through (depending on which slang dictionary you use) radio talk, surfer talk, trucker talk, or the characters in a sci-fi/pop culture adventure.
What's "five by five" mean? No one really seems to know.
"Five by five," and "the Rule of Five," have that in common. Times have changed; has their meaning?
The National Commission on New Technological Uses of Copyrighted Works ("CONTU") issued its guidelines in 1978. The Commission has not re-convened since then; in fact, in 1992, the section of the law that required periodic assessment of 108's impact on libraries, publishers, and content users was written out of the law.
So here we are, drifting along, applying guidelines from 1978. Is that "five by five?" I don't think so.
But I'm glad Libraryworld is keeping the discussion going.
 The rule that celebrities die in threes, which when you think about it, is how we all die (if count long enough, and stop counting soon enough).
 There are of course some other criteria: there must be no knowledge of a commercial use, and the copy must become the property of the requester.
 Or, as some have said, stepped in it.
 NOTE: this guideline only applies to content within its first five years after publication.
 While there is some commentary about CONTU in copyright jurisprudence, there is no case law on applying these guidelines, and in any event, they do not have the force of law.
 NOTE: being open to outside researchers or patrons is required to even qualify for an exemption under 108.
 See Circular 21, page 14, paragraph 3. When you're done wading this answer, "Circular 21," is that place to further explore the nooks and crannies of this issue.
 The very clear case of hospitals using fair use to routinely copy medical journals, Williams & Wilkins Co. v. United States, 203 Ct. Cl. 74, 487 F.2d 1345, 1973 U.S. Ct. Cl, was determined before 108 was adopted. Although the medical facilities won that one, I would not advise that be done in this day and age.
 My money is on that it mutated from telecommunications.
 A Congressional Act of June 26, 1992, deleted former subsection (i) of 17 U.S.C. 108, which read: “Five years from the effective date of this Act, and at five-year intervals thereafter, the Register of Copyrights, after consulting with representatives of authors, book and periodical publishers, and other owners of copyrighted materials, and with representatives of library users and librarians, shall submit to the Congress a report setting forth the extent to which this section has achieved the intended statutory balancing of the rights of creators, and the needs of users. The report should also describe any problems that may have arisen, and present legislative or other recommendations, if warranted.”