I will agree that in Hebrews it directly states that Christ was the once for all sacrifice, ending the Old Covenant's necessity for animal sacrifice to cover sins. As far as the others, I do not see any clear evidence that they went along with the Old Covenant. A covenant is a Blood Promise. In Scripture it was to cover sin. I do not see the correlation between instruments and the forgiveness of sin anywhere in the Old "Covenant". People never could play their instruments without animal sacrifice and be forgiven. It was always a form of worship to God. I also do not see it written that instruments were ever forbidden or suddenly outrageous in the sight of God. I do see instruments in the Old Testament and in Heaven. I think what we can definitely agree on is that God delights in worship, which is an attitude of the heart first and foremost.
Any thoughts?