Most Catholic PIPs in the USA would greet such an admonition with non-cooperation, shall we say. It's a function of the governance culture of the Catholic Church: the PIPs get an overt say in very little, so when faced with a new command that is gilding the lily, they tend to exercise their power of non-cooperation. It can take a while for new pastors to learn this hard lesson, let alone lay ministers. Organ or musical solos before and after Mass survive on the sufferance of the PIPs.

It's movie theater etiquette. Who stays for the whole credit reel/closing theme?

So, the upshot is: if we hid a bonus cartoon at the end, people would start to stick around a bit longer.

About the closing voluntary -
I can't imagine an entire congregation staying for the voluntary, maybe, maybe , some of it, but not all of it.
That said, it is not at all uncommon in many places (less likely to be Catholic ones) for a cadre of organ and music lovers always to stay for the voluntary, some of whom even gather 'round the organ in rapt appreciation.
Particularly at evensongs, which are a rather special case, nearly everyone will normally stay to hear the voluntary. It is, after all, a musical offering to the Most High.

About all stanzas of the dismissal hymn -
There are probably relatively few Catholic churches at which the entire congregation will stay for all the stanzas. There are laudable exceptions, though. One is St Basil's Chapel, at Houston's UST. It is the teaching of the campus chaplain that this hymn is part and parcel of the worship. The people stay and enthusiastically sing - even if it's all seven or so stanzas of Crucifer.
Too, of course, it would be unheard of and unthinkable for anyone to leave at Walsingham before all stanzas have been sung. I would expect that this would be true of all Ordinariate parishes - it's our tradition.

Biting my tongue, lest I say something awfully negative, let me say that a mountain of catechesis is desperately needed with regard to Catholics and their participation at mass, this and their depth of comprehension of the mass as a continuum of prayer, adoration, and praise - rather than a series of 'now we do this, and now we do that'. There is little understanding of the entire mass as an unfolding unity. The worst enemies of this, aside from pitifully poor catechesis, are announcers, cantors who call attention to themselves, clergy who insert their far from priceless comments, announcements, and so forth: distracting things that mercilessly interrupt the sacred action and frustrate spiritual flow and immersion in it.

Music Organist wants all to stay for Closing Voluntary

Blogger wants people to Send Him Money for No Reason

People may linger for a Daquin Noël.

In an idealized notion Charles Tournemire thought that everyone should stay after Mass to hear the piece terminale, which was a resume of the day's thoughts musically. Those pieces contain not only some of the chants of the Mass, but also bits from the offices also. Like I said, an idealized notion......

I rather like Tournemire's attitude as offered by kevinf to the not-so-nice one held by some, namely the 'the mass is over so it really doesn't matter' syndrome. I find this latter an unfortunate and somewhat cynical stance unworthy of any whose vocation is that of church musician. Any and everything within, before, and after, and in any way associated with the mass is excruciatingly important as gorgeous creative raiment to the most sublime, potent, and splendid of human-divine actions. It matters! Tournemire said it just right. Thanks, kevinf.

I am less annoyed by the people who leave and more annoyed by the people who stand in the center aisle and TALK VERY LOUDLY.

I have one diva soprano who has been heard yelling over the organ for the last 10 years. I know she has nothing so important to say it has to be said at that moment. I just play louder.

That would be illegal in the USA - a violation of local fire codes: the First Amendment is no defense to that. A pastor who did that should be corrected by his bishop (and insurer) - quickly.

A priest that I know yelled at the congregation for not remaining until the last verse of the closing hymn. Another priest made a more civilized speech, and at the end of that mass, one woman who was very obvious walked out right after communion, and heads were turned in that direction for the rest of the mass.

"The doors! The doors!"

thumb their noses at their fire codes and insurance policies

and safety and decency

If you only follow fire codes out of respect for civil authority, or fear of civil punishment, you're an [insert anatomically-based vulgarity here] and are unfit to be in a pastoral role of any kind.

Make it seem like it matters, and the people (not all, but some) will start to behave like it matters.

Does it matter? Isn't this part of the big debate "Are hymns an important part of Mass or do they mainly accompany a liturgical action"?

Recently we had some words from the pulpit about making a proper thanksgiving after Mass, and I think people don't dash out much any more.

Widor Toccata? I myself would get out as quickly as I could :-)

On the other hand, Charles, are you making an offering to God, to your pastor (who isn't God) or to the self-appointed committee of malcontents who lurk in many parishes?

Chonak? Could you reduce the over-posts, please?

Mr. A____ always stays for the entire postlude at the 9AM Mass, the W____ family always stays for the entire postlude at the 10:45AM Mass, and the F____ family always stays for the entire postlude at the 12:30PM Mass. If any of them leave before the postlude is finished, I know that it was way too long.

Maybe the congregation can make a deal with him: shave that silly chin hair off and we'll behave during the closing.

I've read somewhere, not entirely sure where, that the recessional is to be sung 'while the people leave the sanctuary.' In other words, they aren't supposed to stay for all the music. The music is, basically, to cover the noise of their leaving.

It is a recessional, after all... =)

I'd rather people leave during the recessional hymn, than stay and talk loudly.

I'd rather..... than stay....

I'd rather have them stay and sing loudly.

Well, Liam - I rather like the singing... but... um... something about the text!
Maybe, to exercise charity, the captionist has a hearing (or discerning) problem???

Next Sunday, in a chapel where I direct the schola cantorum and play the organ, we plan to finish the schola/organ program with the simple form of Salve Regina intoned by the celebrant and chanted by everyone (priest, acolytes, schola and assistance), followed by Piroye (attributed to) 'La Royal' while to procession goes out in sacristy, in musical allusion to the last mystery of the Rosary, for an External Solemnity of the correspondent feast. In ordinary Sundays, part of assistance usually leaves the chapel after the procession goes through the sacristy door and after a brief and personal thanksgiving; others stay until the celebrant leaves the sacristy for the second time, after going back for some personal kneeling and praying himself. I usually do a brief postlude, avoiding the organ or a chanted hymn to be sounding too much long after the final procession, not to bore too much those thanksgiving actions. But in the case of festive Masses (patron of the chapel feasts, first class Masses, solemn or pontifical celebrations, first local Mass of visiting newly ordained priests etc), we use to lift organ/chant limitations and put them to sound as long as the announced program at the board fixed Chapel entrance. I have never metered, nor asked someone to do so, how many and how fast people leave the chapel while those programs are performed, but after postludes of 6+ minutes, only a few stay inside. I live with this phenomenon without problems. First of all, those postludes are not part of the Mass itself in strict sense. Also, in a relatively new traditionalist community, many people are not enough musically educated yet to appreciate those music nor to take their suggested mood for praying and meditation, and so making them to stay for additional 5 to 12 minutes. And above all, the program is offered to God, in humble expectation that, pleasing to Him, graces would be given to all the assistance, had they listened to all the program or not.