As far as Christians are concerned, the OT is not our authority. The OT is important, as I have already shown, for us to learn about God's plan for mankind. There are many great lessons in the OT, but we are now under a new covenant. Nothing in the OT is binding upon a Christian.
"Nothing in the OT is binding upon a Christian."
Really? That isn't what Jesus said. He released Christians from some things, but did not abandon the Law. It sounds to me like you are taking a very narrow stance on this.
In your view, even the 10 Commandments have no force for Christians. I doubt very much if that is the intention of Jesus' teachings.
What you appear to be doing is taking Paul's instructions to the early church and applying them whether they agree with Jesus' own teachings or not. What is not prohibited is allowed, and instrumental music was used, even in David's time. I doubt seriously if Jesus would have objected to Bach's B-minor Mass. Nope.
Except that Jesus Christ, by his own declaration, is the fulfillment of the Law and the Prophets.
If they have no authority, then neither does Christ.
So there IS a way out of the 10 Commandments!
What you are trying to say is true but only in a very limited sense. Regarding salvation the only thing that is binding is "believe on the Lord Jesus Christ and you shall be saved" and "Ye must be born again" and "The work of God is to believe on the one He sent".
Even the greatest two commandments are not binding in the sense that every sin is a failure to perform them, but our salvation is secure in Jesus.
Other than the issue of salvation your statement falls apart. Thou shalt not steal is not binding to our salvation but there will always be a consequence and that is from God.