Copyright is a barrier, but not the only barrier. For example, Hollywood is finding out the hard way that all the LTO tape libraries they bought to archive mov

Copyright is a barrier, but not the only barrier. For example, Hollywood is finding out the hard way that all the LTO tape libraries they bought to archive movies onto are incurring large migration costs, since nobody makes the same format tape drives for multiple decades. Every other digital storage medium also requires periodic data migration. The assumptions and budgets of pre-digital preservation projects was that "archival conditions" and original (non-exploding) media was enough. The ideas that you're probably having in your head - i.e. of using BitTorrent and the hard drives of strangers with a data hoarding addiction as cultural preservation - would have been absolutely ludicrous any time before the Internet. Nowadays it's vaguely feasible that at least the Internet Archive or Wikimedia could handle the data storage requirements for full-take cultural preservation. My personal opinion is that these sorts of modifications to a creative work to dodge a relicensing obligation should be prohibited by some kind of moral rights regime. The original creators are being done a disservice by having the music stripped to cut costs. But the US in particular is extremely hostile to that sort of thing (despite having agreed to implement it in treaties).