Bloomberg, Apple is going to parnter with Shazam to make the feature work. The report says that users will be able to ask Siri something like "What song is playing?" in order to launch the feature, which would also be closely tied to iTunes Radio. Basically, the report makes it sound quite a lot like Google's song search feature that first existed as a widget for the Play Store, and was later built into Google Now.This would seem to be a job for the Siri team at Apple, and the report does indicate that the feature would exist as part of Siri; but, according to
The report only mentions Apple partnering with Shazam for song identification, but it should be noted that Shazam doesn't just do music, but can also be used on TV shows. Currently, that feature simply brings up info on the show from IMDb, but we'd be surprised if Apple weren't also hoping hook that into iTunes. It's always better to push users to where they can purchase content, rather than just learn more.