I can say, unfortunately, that many of us on this forum have been where you are. I was recently there: attempting to bring true Sacred Music to the parish where I was the DM. If you have been following my posts, you will already know that I resigned about a month ago. A few points:

1. I agree with you that there is a prevailing attitude among Catholic Churches in the US that "contemporary" music and P&W are somehow better than Sacred Music: Gregorian chant, etc. My only observation on this is that there is also a prevailing view in Western culture that music is for entertainment, so if people don't like it, then it should be changed. Of course, the problem with this attitude is that when we're attending Holy Mass, we're not at the opera house nor in the concert hall and the paradigm changes completely. If I was singing on the stage at the Met, then maybe I'd be somewhat concerned about whether or not certain people (not everyone, of course) liked what I sang, but at Mass, never. It's not about likes or dislikes at all. The issue is the aforementioned cultural view that music is always about what someone likes or dislikes: after all, it's just for fun, right?

2. People don't want their songs: just some people want their songs. As the very wise, much more wise than I, on this forum will tell you time and again, it is the small percentage with big voices that sway the Pastor to change what you do to fit what they think should be done. I've been studying the GIRM recently and coming up with my own views of what is wrong with the OF, and my prevailing conclusion is this: there are too many options and no objective standards by which to judge them. Everything is done per somebody's whim. This has the added danger of opening the priest to negotiation and manipulation, whereas before his hands were tied by the rubrics: he couldn't grant certain requests because the Church said so and it wasn't his decision.

3. You will find it difficult to get a post when you're offering something that isn't understood or desired. Sometimes, it is helpful to consider who is interviewing you for the job. It could be:
A. a committee of laypeople charged by the Pastor with finding a replacement DM. This group probably doesn't even know that the GIRM or SC exists, much less know what they say about Sacred Music. They also are more likely to view music with the entertainment mentality because the chances that any of them are trained musicians is slim to none.

B. the Pastor himself. If this is the case, you are simply at the mercy of whatever the pastor's view on music actually is. I would seriously consider asking pointed questions, beginning with the following: What is the purpose of music at Mass? Depending on what he says, you will get a clear indication of whether you actually want the job or not. Some of my colleagues will remind me following this statement that some people don't have the choice because they don't have another source of income other than serving the church as a musician. In this case, you have to carefully balance your principles with your priorities. Sometimes, you have to sacrifice principles for priorities: we've all done it before. Either way, the decision is still yours to make and I wouldn't be able to accurately advise you on this aspect.

4. I'm not sure where you live, but try to find an FSSP parish. Around here, they only offer the Extraordinary Form, and love to hire musicians with experience in Sacred Music. I almost landed a job as a DM for a nearby FSSP parish, which would have been a significant improvement over my old position. There is a light at the end of the tunnel, and that light is Jesus Christ. Christ appreciates what you do, and so do we. Keep fighting the good fight: you'll be rewarded in the end.

I would take the position with FSSP ,but i did not found available positions.

There's a lot of wisdom in what bonniebede just said. I am essentially doing the same at my home parish where I am also the music teacher at the school (someone else does the music for Mass on the weekends). I have taught the children's schola to chant, and we sing the Offertory proper and Communion proper for the school Masses. The best part is NOBODY COMPLAINS, not even the priest. We do a Gregorian ordinary for Advent and Lent (which I don't agree with, since we should be doing a Gregorian ordinary all year round, but that was the priest's request), and we will be doing Latin propers from the Graduale Simplex this year during those times as well. Working with the children and teaching them true Sacred Music is the way to ensure it happens in the future.

Yes, I am directing children's Schola , we have great unbelievable results with parish all choirs.
P: - We are losing parishioners because of the music.
Me: -The sacred music that Catholic church used for many centuries?
P: - They want their songs {from Folk Mass of 70th}.
Me: Are the parishioners coming and leaving because of a few songs ?
P: -Those songs are approved by USCCB.
Me:-Pope Benedict considered such style (70th)as the opposite to sacred.
P: -We will use it as long as we have it in hymnal.

@condorg
Forgive me if I don't prima facie accept your caricature conversation as exact.
Do you understand that if you have a command of the breadth of repertoire out there, and can exercise a non-exclusive attitude towards evaluation of said breadth, that only then can you address the simplistic response of your pastor, which I doubt is completely accurate as you report it? This repertoire means from Kindergarten to Advanced Schola. The blatant reality you cite, "I do not care what you think..." from your pastor can only be successfully mitigated by your leading him out of his/and attack sheep comfort zone by exhibition of your fully informed knowledge of options. You've painted yourself in the corner. That's irrational. You need to earn trust not by capitulation but by persuasion. And you have to know your sh*t beyond whatever this book or that organization says is "Da Rules." Others here have oft decried me of such pragmatism, but I think in their heart of hearts they know that liturgical paradises cannot be forged without mutual consensus of lay and cleric. If you can't learn to play ball, then by all means follow Ian's advice and look for an FSSP joint. But be aware, they play politics too.

coherent yet varietal

A desire for variety implies to me that someone wants to be entertained. It's not interesting enough as it is, so more variety is demanded.

he allowed me a lot - Propers, good music, Chanting kids till he became aware that ANY natural change of demographic or seasonal attendance or even cataclysmic changes in area jobs market- he really sure that the High Music that is so annoying him personally, would be the only reason of collection' reactions.

Something very similar happened to me, only it started with a disagreement over Latin in the liturgy. When I began my employment, the priest allowed Latin, but after about a year or so, he completely banned it. Then, after that, he didn't want to hear any suggestions regarding what we would term Sacred Music. I even tried to water it down a bit, by suggesting very simple changes (SEP, Communion only, followed by familiar hymn, everything still in English, etc.) He just simply wouldn't hear of it. He even told me face to face: "Nothing too traditional." To this day, I can't figure out what changed his mind. Again, it's really all up to your priest, and for better or worse, it's all completely legitimate per the GIRM. The benefit here is that not all priests are the same, and some will permit more Sacred Music than others. You cannot control what someone else does, but you can control what you do. At the school, we have some very big personalities that attempt to usurp authorities that they do not have the right to. Sometimes, younger teachers will approach me about these types of situations and this is the advice they get from me: ask yourself this question: "What are you going to do?" This is really the only question you can ask, because you cannot in any way force another person to do anything. So, in these types of situations, ask yourself that question: "What are you going to do?"

There are aspects to your story that would be a flag that you may benefit from in-person counseling - both in terms of professional development and managing frustrated aspirations.

I am not talking about mental illness. I was specific to professional development and managing frustrated aspirations. Quite different. Many many people in mid-life who started in a career and found themselves dead-ended can relate. But the internet is typically a bad place to explore profitably in this regard.

An old expression, if you don't mind. Don't saw the limb in half that you are sitting on. Do what you must to stay employed while actively looking for something better. I have no problem taking the devil's money. I can put it to better use than he can. However, it is better to leave on your terms instead of on someone else's.

Edited: it appeared the sacred music program was only repressed because of tensions in parish which had nothing to do with the music ever.

Ah, thank you for the clarification Melo. I mistook it for more of the "variety show" sort of "variety," complete with Stadler and Waldorf types approving or disapproving the presentations.

YMMV, but I did that at my former parish and I found myself ducking the Pastor a lot so I wouldn't have to talk to him. That is clearly a red flag that I needed to resign for my own sake.

As it happens, I have visited the parish which the original poster is writing about.

At the Sunday Mass, the priest's homily consisted of a 17-minute harangue, with a sustained tone of anger throughout, followed by his attempt to sing an inspirational song.

I get the impression that this is a pastor whose manner drives away parishioners, but who blames everyone else for it: the musicians, the staff, the congregation itself, etc. Probably everyone who works at the parish is suffering from emotional mistreatment.

Here's my take on this. Because the church is a hierarchical institution, (one of the last true remaining such animals) If you don't work with this in mind, you are sunk. Our pastors, bishops are formed to operate under this paradigm.
Practically that means:
1. The pastor is going to want his likes (right or wrong) and preferences, and expect that since he is pastor, he has a right to this.
2. If you are continually in conflict with the pastor, you will lose.
3. You cannot 'win' an argument against a pastor. If you win, you will lose.
Suggestions:
4. Suggest a compromise. It help is you present a concrete plan. Suggest: Singing the 12 beloved tunes, one a week at offertory, and include better music for the introit/procession. Present a detailed plan on paper. Pastors like a solution that someone has figured out which included their likes. They don't have time to create one.
6. Aim toward a solution that includes what the pastor wants, but don't give up your ideals. Sometimes advancing Sacred Music in a parish is incremental. And it's more likely to stick if you do it that way.

1. The pastor is going to want his likes (right or wrong) and preferences, and expect that since he is pastor, he has a right to this.

And canon law pretty much means that he does have a right to it. Bottom line, it is the pastor who is responsible for what happens. The buck stops with him. His up-lines can write all fine documents they want, his sheep can do all the study they want (in theology, sacred music, finance, plumbing, whatever) - but he's the one who makes the final call.

Of course a very wise pastor will only rarely make a final call himself.

But even the wisest has to sometimes. And the ones still learning often make more decisions than their wiser brethren would.

If you cannot work within the challenges that this setup brings, you should look to work in some other area, because the disciple of the Catholic church is not for you.

To paraphrase Margaret Thatcher: "Being in charge is like being a lady. If you need to tell people that you are, then you really aren't."

@PaxMelodious. EDITED .
RE
"If you cannot work within the challenges that this setup brings, you should look to work in some other area, because the disciple of the Catholic church is not for you."
In reality, let say, pastors X, Y, Z pretty often are not very well understand the doctrines. For example, it was on USCCB web the lyric of Methodist musician attributed to either of Therese "Christ has NO body...but YOURS...". What about basic doctrines? Eucharist? Is it YOURS Body? Etc.
Do many of priests know what first year child studying music knows? Do majority of clergy knows what the organ registration is ?
Good luck to follow to someone ignorant and it is same if you are under the care of surgeon who never learned 4 classes of elementary school . That absurd of following after the unqualified church servants...is a devil.

I have found that whenever I am convinced that a problem has no solution, there is no solution.

Interpret that statement as you will.

It is a comment about nothing other than my own experiences, possibly helpful to others, possibly not.

For example: vowed religious are expected to pledge obedience in all they do, and obey the instructions re assignments and work, but in what sense are lay people expected to do so?

There probably are differences of various sorts, though I don't quite see how they would be relevant to performing the job of a music director. On the other hand, there are always exceptions to the obligation of obedience, even for vowed religious. (If Abbot John instructs Brother Ben explicitly to commit a sin, Brother Ben is not obligated to obey, even though he has a prima facie obligation to obey the Abbot's directives.)

On the third hand, the following advice (from here) seems quite pertinent and sound to me:

Certainly, and not only in the developed world, the days are past when a priest was the exclusive source of doctrinal information. Today, most educated Catholics can find out for themselves what the Church teaches or regulates on any topic.

Yet this extra knowledge should be an aid to mutual understanding rather than a weapon of discordance and the attitude should always be one of construction rather than confrontation.

In any case, the music director, whether vowed religious or lay, is clearly under the purview of the pastor as regards performance of duties specifically related to his or her role as music director, and that's as it should be.

(Edited): That was not "fiction".

I've said as much to many pastors, and never been dismissed.

Yes, I was wondering, and yes, I'm very impressed at the result. I have the feeling that if I'd done that at my previous parish, I would have been shown the door.

Sorry. @melofluent. it is not verbatim or paraphrased or hyperbolic, priest just exactly that very way: to scream into a microphone essentially "Stop! Do it my way!".it is at least not first priest that I met/my teachers met who really "do it my way" while even not to sure by himself what his way is.(..) It is ok though, to have no understanding at forum:-.

@melofluent . I do not feel the particular priest is the rare exception from the rule. He does all songs in his own way and it is very typical way for guitar Mass, Family Mass etc; changing 4/4 March into 3/4 slow blues (that is so typical because of need somehow to strum), adding, stretching or stressing bars etc- very typical for guitar Mass where the leader just learning by rote and then "leading " by voice the entire assembly. What so confused you: I met it as a very typical reaction of one who strummed the guitar in church and was "the leader of the song",so had a years to lead by mic. amplified voice.

and probably never thought that the song might actually be somewhat annoying.

There's your problem: knee-jerk reactions and pre-packaged liturgy.

1- I don't speak with clerics using the same language and tone as above. But I am consistently not shy about addressing concerns. For example, I have a liturgy meeting this morning. I requested "homiletics" be added to the agenda.
2- I take no pride in never having been dismissed. But I could not live with myself if I cowered to a clergyman who personally demeaned me fulfilling my duties.
3- I appreciate Chonak's clarification. I believe that either by reputation or encounter at an interview both the musician and the cleric(s) should be capable of getting a good read on whether that chemistry has possibility in terms of relationship success or toxicity.
4- Were I to ever encounter a celebrant doing the sorts of things condorg describes as having literally occurred, a dialogue Mass would ensue that he wouldn't expect.
5- On the rare occasion I've encountered actual clericalist abuse at a Mass while on vacation, ie. political exhortation, made up prayers including the Euch. Prayer, no Credo, yada yada, I have waited after Mass and informed said celebrant that by his errors of commission he does injury to his parishioners, the Church and the priesthood. Then I walk away.