Possibly Not OK
The actual Creative commons license (Specifically the CC-BY-NC 4.0 license) says:
NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.
An advertisement for anything for which a fee is charged is "primarily intended for or directed towards commercial advantage". I believe that any such use would violate the license.
The license says nothing about who receives any monetary compensation. In particular, it does not limit "commercial" to case where the re-user gets monetary compensation or commercial advantage.
The Creative Commons Wiki page on "non-commercial" says:
The definition is intent-based and intentionally flexible in recognition of the many possible factual situations and business models that may exist now or develop later. Clear-cut rules exist even though there may be gray areas, and debates have ensued over its interpretation. In practice, the number of actual conflicts between licensors and licensees over its meaning appear to be few.
The definition of NonCommercial depends on the primary purpose for which the work is used, not on the category or class of reuser.  Specifically, a reuser need not be in education, in government, an individual, or a recognized charity/nonprofit in the relevant jurisdiction in order to use an NC-licensed work. A reuser that is not obviously noncommercial in nature may use NC-licensed content if its use is NonCommercial in accordance with the definition. The context and purpose of the use is relevant when making the determination, but no class of reuser is per se permitted or excluded from using an NC-licensed work.
Whether the copyright holder would 1) notice, 2) object, and 3) bring suit is another question. Whether such a suit would be successful is also uncertain, in the absence of case law. I can't find any online record of any such suit, successful or not.
In the Creative Commons study Defining Noncommercial it is said that
In sum, the decision-making process is not clear-cut.
However, virtually all creators agree that a noncommercial use is one in which “no money changes hands.” Many then add that for a use to be truly noncommercial, there should also be no indirect commercial gain.
(Pages 32, 33)
The motive (or apparent motive) of the person using the CC-licensed content will probably matter. If the e-user was doing it to advertise the show, because s/he thinks that presenting such a show is a wonderful thing for the community, and is acting as a sort of unpaid PR department for the show, I think that would be a commercial use. If s/he is merely announcing the event, that is different.