Time again to sift through the critical mailbag, for letters and/or calls that didn't go to the editor and other non-ticking missives:

- "I WAS INTERESTED in your column on laser video. I've had a player for some time now and think they're the greatest, especially for operas. But these new PolyGram CD Videos, are they compatible with the Pioneer system? Also, my player isn't equipped for digital sound. Will they still work on it?" - R.P., Provo.Not only are the PolyGram discs fully compatible with existing LaserVision technology, but the discs I've been able to examine so far are in fact pressed by Pioneer - i.e., the only difference is the name.

That means that each contains, besides the two digital tracks, a pair of analog tracks as well. (Look for the "CX-encoded" emblem on the back of the package.) Since each track can be isolated, Criterion is reportedly taking advantage of this feature on its new line of audio-only laser discs to extend the playing time to six hours mono. (Theoretically that could go up to eight.)

As for the new PolyGram videos, we will be reporting on them too, as soon as that company sees fit to submit some for review.

- "WE REALLY ENJOYED your report on film-music CDs. No one else around here seems to pay much attention, including the record stores. Where can we get some of these things? I haven't been able to find `The Best Years of Our Lives' anywhere." - H.H., Salt Lake City.

As it happens, I had a similar query on the Utah Symphony's recording of "The Sea Hawk" a few months ago, which even the symphony office didn't seem to be able to supply, on CD anyway. (A couple of copies recently surfaced at Raspberry Records.) So my advice is to first try your neighborhood record store - Fifth Contentent, which produced "Best Years," does have some local distribution. If that doesn't work, you may write the company directly at 1200 Newell Hill Place., Suite 302, Walnut Creek, CA 94596.

- "I BET YOU'RE glad the symphony strike is over. Do you think they're out of the woods now?" - J.B., Salt Lake City.

I seem to have heard this question almost every week for the past three months, so maybe I should respond publicly: Not only do I think they're not out of the woods - they may be in deeper now than they were before the strike.

I say that because I believe the management was right: At present, without dipping into the endowment principal, they do not have the money to meet their current contract obligations.

The math on this is pretty easy. Despite bringing in contributions in excess of $1.7 million last year, the symphony still finished the season with a deficit of $280,000. That means that, even had things remained status quo, this season the board would have been obliged to come up with around $2 million.

Of course things are no longer status quo. Among other things the musicians obtained salary increases of 1.9, 3 and 7.4 percent over the next three years. Unless revenues are correspondingly increased - not impossible, but highly doubtful - that will also have to be made up via contributions, as will the gains in seniority pay, now $5 per week for each five years in harness. As one of our correspondents reminded us a few months ago in a "My View" column, it was an agreement like this - i.e., forcing the board to commit itself to expanded funding and then trying to find it - that put the Nashville Symphony out of business.

But I also believe the musicians were right, at least in calling attention to the dangers inherent in the kinds of cutbacks the board proposed initially. Not only would the artistic status of the orchestra have been appreciably lowered (important in terms of the kinds of players and conductors it could expect to attract and hold in the future), but the history of orchestras that have gone that route is no more encouraging - for example, the Oklahoma Symphony, where two years of "temporary" wage freezes and ever-deepening cuts finally put an end to 51 years of concertizing.

So obviously the answer is more money, whichever way the ax falls contractwise. But I wish I could be more optimistic about the chances of raising it, and about the blessings that come as a result. Consider the plight of the Baltimore Symphony, whose phenomenally successful funding effort - to the tune of $40 million - was also rewarded with a strike, at last report going into its 13th week.

A thank-you like that would make anyone reluctant to contribute.

- FINALLY, TO THE GENEROUS soul who sent me a certificate for a free hearing test (presumably on the assumption that I needed to have my ears examined): I passed.