[discostrings]

Right before checking HN, I'd spent a few hours thinking about how to approach this very problem!

Where are you fetching or how are you determining the track IDs for each service? Is it a simple metadata search through each API, are you using some of the reference data from Musicbrainz, or is there another good source of these relationships available?

The Echo Nest used to have a great open-access API for cross-referencing track IDs called Rosetta Stone. Unfortunately, Spotify discontinued it a few years after acquiring The Echo Nest.

While I understand why the streaming platforms might think it's in their interests to make cross-service track relationships difficult to determine, I'm disappointed that Spotify shut down a useful service that really helped music lovers. From some brief searching earlier today, it looks like no one has taken up the mantle yet.