Apple has a search API that allows you to query the iTunes Store for music:
https://affiliate.itunes.apple.com/resources/documentation/itunes-store-web-service-search-api/
Here is an example search: https://itunes.apple.com/search?term=jack+johnson&entity=song
An ISRC code allows is a standard identifier for song across markets (https://en.wikipedia.org/wiki/International_Standard_Recording_Code). Spotify for example returns the ISRC in their api.
Is there anyway I could get this code for an iTunes track? If Apple does not provide it themselves, is there someway I could find it using the metadata that they do provide?