In an essay on Richard Strauss, Glenn Gould proposes the following thought experiment:
Suppose that a talented musician were to improvise a piece in the style of Haydn. A good solid piece of work, drawing strongly on the musical idioms in which Haydn worked, a fine piece of music and distinctly Haydn, or at any rate Haydn-era.
If the musician was truthful and passed the piece off as a contemporary improvisation in-the-style of, it would be treated as a fine piece of work, but ephemeral. Almost nobody would remember it in a year.
If the musician instead passed it off (successfully) as a previously unknown work of Haydn, it would be accepted into the canon, featured in Haydn performances for a while, and then blend seamlessly into the rest of Haydn's catalog.
If the musician instead passed it off as the work of Mendelssohn, a slightly later composer, the reaction would probably be more negative. This is inferior Mendelssohn, probably from his youth. A mere aping of an earlier era. It would rarely, if ever, be played.
Finally, if the musician passed the piece off as a work of Vivaldi, who was working 70 years earlier than Haydn, the work would be greeted as a triumph. Proof of Vivaldi's genius, that he could reach into the future and deploy musical vocabulary so inventive and fresh, so far ahead of his contemporaries. It would be played frequently, it would occupy a prominent place in Vivaldi's catalog.
Glenn Gould had many problems, but lack of erudition and lack of understanding of contemporary classical music culture were definitely not among them. We may take his discussion as entirely accurate. What he is driving at is that the provenance of a piece figures largely in how we experience the piece (and also that music critics tend to place too much importance on provenance). The same is true of any art form.
The provenance of a piece certainly affects one's experience of the piece. My attitude is that art is essentially about the viewer's (or auditor's) experience of it, so I cannot discount provenance. We experience a Weston print differently if we know it to have been printed by Weston himself. The experience varies according to whether we know who Weston was, and whether we think of him as a master printer or not. In all cases, though, the little note next to the frame reading "the man who took the photograph also printed it" surely has some effect on us. Provenance is one of the many pieces of context surrounding a photograph, it affects our experience of the photo in much the same way adjacent text does.
We could argue at this point about whether provenance is truly part of the art-ness of the piece or whether it is merely contextual. While I am drawn to argue the latter, I can see no way in which that discussion is not the merest of pointless semantic wankery. I enjoy semantic wankery, but try to keep the mere sort out of this blog.
Nonetheless, we need to be cautious about provenance. While we surely experience a Vermeer differently knowing that it is a Vermeer, we should not blather on about how only Vermeer could have executed that brushwork. We experience a Cartier-Bresson differently, knowing it to be Cartier-Bresson, but we should avoid making claims that only that photographer could have captured that circumstance of geometry. The brushwork is good, or it is not. The geometry is good, or it is not. The light is handled superbly, or it is not. That one artist did it and another did not affects the light not one whit.