There seem to be at least two questions being answered here, and the answers need to be different.
The original question related to how an archive library should preserve historically significant information.
The "creep-in" question is how we can preserve our personal music accumulations.

The question of how to keep our personal stuff is probably the easiest.
One approach is to get two copies of everything, and put one in good storage. An easy, and usually cheaper, alternative, for the fragile stuff like tape and records, is to immediately copy them to tape and "archive" the original. The critical thing is that with both tape and phono records, every time you "read" it, you probably make an ittybittyteenyweenyatomisticundetectable (yellow polka dot?) change to what's on the original, and the changes accumulate.
Even in storage, though, phono records and tapes lose some of the data. I have a number of older 33s that have been in safe storage for about 20 years, and even on the best of turntables they don't sound as good as they did when they were new. (Some of the tapes I made then and used fairly often actually sound better now than the original disks.)
Those who have the equipment to do so might want to put things onto a CD. Those who are really "gunh-ho" about it all might make one CD for storage and one to play from. For all practical purposes, relative to the life or interest span of the majority of us, this can be considered "permanent archiving." (Another advantage of that "master" CD that you put in storage is that you might be able to find it when the "emergency" comes up.)
If you are going to do more than that for a personal collection, it is VERY important that you have named your executor and know that he/she is informed about the specific historical collection that will get your stuff (and your excellent index) when you're gone.

For the historical archivist, the whole deal is a lot more complex. CD manufacture has been around for long enough to be a little better than black art for audio CDs. It may be expected that these will be playable for a fairly long time.
For the "permanent historical" archiving of text and artwork, the situation is a little different. The first consideration is that the information has to be "made digital," and there are a number of different ways of doing that. At least one company, Information Handling Services (IHS) or something like that, has been leasing CD jukeboxes for about 15 years on which you can read almost any specification or standard known to man, if your company is willing to pay the lease fees. This makes it appear that there is an "established" standard for how to do it.
The appearance of "utility burners" on PCs has clouded the situation somewhat. The CD writers used on PCs come in several forms, and there are at least a couple of standards in use. The situation gets a little more muddled when you talk ReWritable CDs, where 3 or 4 (if it's still Tuesday) competing standards seem to have about equal chance of surviving. If you go on to digital TV (DVD is only one of several) recordables and/or rewritables, you get into a maze of different standards and methods.
The current crop of PC devices all attempt to address compatibility issues, but the best that can be said is that "some burners" using "some brands of blank disks" can make CDs that can be read or played by "some players." The only useful advice I've seen is "when you find something that works, stick with it."
For the historical archivist, the thing to be feared is that one of these "systems" (the one with the richest backers, probably) should eventually emerge, and could obsolete what works now for them.

SAVE OFTEN, AND PROTECT YOUR BACKUPS!
The index for the Microsoft Windows 2000 Professional Resource Kit shows 59 entries under the general heading of "backup." This shows how very important this is!

RESTORE YOUR FILES TO CURRENT MEDIA AT REGULAR INTERVALS!
The index for the Microsoft Windows 2000 Professional Resource kit show ZERO entries related "restore."

Maybe they'd like to forget some history?

John