Steve D.
GR is clearly stated to be a 'field theory' and that field IS Spacetime. There are many that wish to equivocate both SR and GR with something they originally came to conceive, but which is more a collection of naive intuitive ideas.
It is the selection of several maths that express different aspects of field properties and response which are the "tools". But if you start by making GR fit your ideas instead of learning what GR is about, it all falls apart. Though it is not a complete theory, and Einstein never claimed it to be, it should not be confused with such developmental evolutions of relativistic thinking such as Blocktime. Incomplete as it may be, the extent to which GR can go to adequately describe and predict existential phenomenon is wholistically integrated.
And as one of the most consistently successful theories ever devised, the onus is on those with competing notions to categorically show mathematically how their results agree with the vast redundancy of observations that have accumulated over the past century of application and refinement of measurement in General Relativity. Both SR and GR rest solidly, and intentionally, on Maxwell. The postulates were not something drawn from nothing as a convenience to be put in by hand. You of course are free to follow your own ideas, but no one is required by scientific discipline or civility to indulge in arguments which divest GR of its inherent theoretic structure and reasoning. If people find some agreements with your musings on the 'Music of the Spheres" be happy with that, but I really doubt that many are ever very much swayed by arguments coming from a competing paradigm. best wishes, as always jrc