Right. And, that’s true with identity as well: to some extent, uniquely identifying something is a search problem.

This is a somehwat spacial way of looking at it, e.g., there’s potentially a big space of information, and there’s a question of how one locates information in that space.

There’s also a temporal way of looking at it, which is: how can people get the information they need just in time. (Or, what are the implications / consequences of the time it takes to get needed information.)

There might be a cart before the horse issue with this topic in that it may make more sense to address the temporal aspect before the spacial.

For example, when are the right times for someone to have the opportunity to “pay” for a work of music; or when are the right times for a creator to ask for “payment”? (I put “pay” in quotes, because we might be talking about cash, or we might be talking about some form of trade, reputation, or other non-cash exchange.)

The non-free-market for music online has resulted in a situation where it’s mostly faster to get music files than to get and process information on how to “pay” for the music. iTunes success is partially the result of reversing this situation within it’s own centralized / contained information space.

…and that’s why XSPF has this concept of content resolution as a query operation.

I think a robust system would combine multiple central registries with overlapping data, and some very Internet-like distributed identifier mechanism, e.g., DNS-based URIs (aka web URLs) that individuals can create themselves to identify their works.

For example, a central service could create a digital works registry that takes URLs as input. Those URLs could then be used as IDs embedded in media files, etc. And, the central service could be queried with other identifying info, e.g., a sound fingerprint, to retrieve the URLs when they get misplaced.