From time to time I'll receive letters from readers asking, "Is such-and-such score available on CD, and if not, when will it be released?"
Why aren't some soundtracks on CD? For scores entirely unreleased, the main obstacle is the union re-use fees. Whenever a score is recorded with a union orchestra in Los Angeles—which is most of them—a fee has to be paid to the session players, a percentage of their original salaries, if the music is to be released on an album. This fee is so significant—anywhere from $20,000 to $100,000+ (a vague guess) depending on the ensemble and number of minutes released—that no label can afford to pay it on such scores as Journey of Natty Gann (Horner), Big Wednesday (Poledouris), The Poseidon Adventure (Williams), etc.
Keep in mind that the market for scores like the above three is extremely limited. We're talking a few thousand people. When a new movie comes out, it is accompanied by a regular amount of hype as to make a soundtrack album financially possible. But for an older movie that's virtually unknown today—forget it. It won't sell enough, so labels wont' release it.
(Also, because re-use fees are paid in blocks of 15 minutes [it varies, but let's use 15 minutes as an example], Varèse can only afford to pay for 30 minutes on such CDs as Chain Reaction, Dante's Peak, etc. It's not as if they want to issue 30 minute CDs, it's simply all they can afford. There are also re-use fees in England, but they aren't as high. There are no re-use fees in other European countries and in non-union American states like Utah and Washington, which is why a score recorded in Munich, for example, is certain to have an album, and a long one at that.)
The good news about re-use fees is that once they are paid for an LP, they need not be paid again for a CD. So, why aren't some of those great LPs reissued on disc? It depends on the particular company that owns that album, and their interest in either issuing the scores themselves, or licensing them to other labels. MCA owns the album to Young Sherlock Holmes, but they figure that if they released it on CD, it would not make enough money to justify the effort—they can make more money on some other project.
In addition to these two main snags of re-use payments and disinterested copyright holders, there are many other entanglements that can prevent a CD of a score: missing or damaged master tapes, legal disputes between affected parties, or simply the political shenanigans of different companies.
Rest assured that eventually, these things will find their way out. Since I started Film Score Monthly in the early '90s, literally dozens upon dozens of sought-after scores have become available on CD: everything from the complete score to The Empire Strikes Back to Conan the Barbarian to Silverado to The Day the Earth Stood Still. It's extraordinary, really.