Audio Recording should not be merged with this site, or added to this site's scope.
First, audio recording will be covered by the AV Production site. If the AV site crashes and burns, that's a discussion for then and not now.
Second, it would be bizarre and confusing for AVP to cover non-music audio and for us to cover recording music. There's a huge overlap in the techniques, technology, etc. and there's no reason that people with expertise in recording audio shouldn't be able to talk about recording music.
While it's true that many musicians have recorded music and have expertise in that area, I would expect audio engineers who record music for a living to have greater expertise. A much larger group with expertise in recording music should be present at the AVP site.
And, while it's true that many musicians may have questions about recording their music, StackExchange makes it easy to direct them to the Audio site. Moderators can also easily migrate questions to that site. A large proportion of AVP users will be able to answer their questions, as opposed to the small proportion of musicians who have done serious audio production.
I also disagree with others who think music recording, or apects of it, should be on-topic on both sites. That makes for confusion and a division of expertise. There's also no clear line between the audio-engineer-technical-aspects and the musicality-aspects, and drawing one would be likely to alienate people. Technicians wouldn't react well to being told they aren't "musical enough", and that sort of thing.