The fact of the matter is that ALL musical instruments are played "from the heart" be they stringed instruments, wind instruments or percussion. The voice is merely a wind instrument. If you want to be technical it is a reed instrument similar to a reed organ or a harmonica. Air goes through the pipe and there is a vibrating reed called a vocal chord which triggers vibrations in the air which create a song from the heart. The same can be said for a saxophone which simply does the same thing that the human voice does, but it does it using a bamboo vocal chord. An organ does the same thing as whistling.
Keyboard and stringed instruments are played from the heart through the fingers.
God made music. He admonishes us to use whatever instrument we can find to worship him. Those to whom God has given a talent are admonished to use that talent to the glory of God. All God asks is that we worship him in spirit and in truth and he does not prohibit the use of musical instruments in his worship. Indeed, if he did, then David was not a man after God's own heart as God proclaimed and that would make God out to be a liar.
I could care less if your church prohibits the use of musical instruments. That is your perogative. But I will not sit idly by while you condemn the hearts of those who by the grace of God are gifted in the playing of musical instruments and who use those god given instruments to the glory of Almighty God.
Your silly doctrine is a doctrine of men not of God.