Constitution says nothing about barrel loading, smooth bore muskets. It says "arms". It's a fairly timeless umbrella term for "weapons or objects usable as such". The only people who have trouble understanding this are generally those who approve of the Machine gun registry being closed by having the federal expenditure to maintain it set to $0, and don't that as being an example of "infringement" of a Constitutionally granted right.
It also says “the right of the people” a phrase understood in every other part of the constitution and its amendments to refer to the individual citizenry. Notably, you don’t need to be a member of the press to exercise a right to free speech.
It has different wording but I feel like it’s only difficult because of the politics and emotions attached to it. If it said instead:
“A thriving community of professional musicians, being essential to the existence of great art, the right of the people to keep and play musical instruments shall not be infringed.”
I really don’t think anyone would be arguing that it restricts the right to keep and play musical instruments only to people who are already professional musicians.
A rule saying you already need to be a professional is unreasonable in this scenario. But I think a rule that you have to engage with the community of musicians if you want to have a musical instrument could probably coexist with that wording.