"Then Samuel went to Saul, and Saul said to him, "Blessed are you of the Lord! I have performed the commandment of the Lord." But Samuel said, "What then is this bleating of the sheep in my ears, and the lowing of the oxen which I hear?" And Saul said, "They have brought them from the Amalekites; for the people spared the best of the sheep and the oxen, to sacrifice to the Lord your God; and the rest we have utterly destroyed."" 1 Sam. 13-15
Maybe, since man, seeing only as deep as the exterior/surface, he thinks that prime choice and expensive sacrifices are what God and are acceptable to Him. Although God had clearly explained just how He determines value and from what perspective holiness and good is regarded; "man looks at the outward appearance, but Jehovah looks at the heart." - 1 Sam. 15:7
If more of "Christians" today understood this principle, there would be much more singing and praising God, from the heart, and much less man-made instruments of music, clapping, yelling and dancing in today's worship.
Nevertheless, because man L O V E S his man-made melodies and rhythms so much, the simplicity of what God deems as righteous and holy grows increasingly expendable, while the sanctity and solemnity or worship plunges head-long in decline.
""For My thoughts are not your thoughts, nor are your ways My ways," says the Lord. "For as the heavens are higher than the earth, so are My ways higher than your ways, and My thoughts than your thoughts." Isa. 55:8-9
Let's face the facts, please! Pianos, drums organs, etc. are ALL for man's pleasure rather than God's. And, by realizing and acknowledging the TRUTH that in "singing and making melody in your hearts unto the Lord" Eph. 5:19, we fulfill the Word and the will of God, and He is pleased.
"Coming to Him as to a living stone, rejected indeed by men, but chosen by God and precious, 5 you also, as living stones, are being built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ." - 1 Pet. 2: 4-5