There is no proper answer to your question, for the ship of Theseus paradox is used to illustrate the need to define parameters of identity, which you haven't done.
From the standpoint of a record company and copyrights, yes, it might be ruled the same band. Two individuals might be considered "fungible" as adequate drummers, say. From the standpoint of a fan, perhaps, the band is totally different.
The same goes for the identity of a nation, for example, or any individual, whose bodily cells are replaced faster than their driver's license. As John Locke noted in a famous example, the entire makeup of our personal memories may change over time, which has ramifications for legal and moral responsibility.
The ship of Theseus is a physical object, and it illustrates that even in physics, which must employ "concepts," the conceptual whole is not at all the equivalent of the parts. At the atomic level it's all a Heraclitean stream held in place by our powers of conceptualization.
The point being that the relations between form, function, identity, and composition (or Aristotelean "causality") are complex, relative, and open to skeptical analysis.
So, the identity of your band can only be settled by reference to some defining parameters, such as copyright judgments in a court of law, where this ancient paradox is, indeed, always a live issue. In divorce court Phaedra can honestly argue, with full biophysical backing, "this is not the Theseus I married."