The problems with music is mostly the lyrics. It does not matter to God if we worship with a trumpet, or a guitar. He loves cymbals and harps.
The words of some songs today have filth, sin, licentiousness, ... garbage. Some take the name of the Lord in vain, some worship the devil, some encourage violence and murder...
The book of James tells us 'out of the same mouth proceeds blessings and cursings, this ought not to be so...'
So, if everything is pure, is blasphemy pure coming out of the mouth of a so called 'saint'? Would God justify hatred, because one claims to be saved? No... the 'all things are pure' is speaking of the meat prohibitions of the O.T. which God has now cleansed ... as an illustration of the cleansing of our persons from defilement.
God does not justify us singing hatred toward Jesus, love for the devil, blasphemies of our Lord, sexual immorality, licentious, perverted words. Those songs are evil, if they contain that kind of language, even if played on the church organ.
The music, for me, can vary greatly. I love piano music, I like jazz, I like long hair music, southern gospel, not so much Bach, gospel music, hymns, and pretty much any kind of music other than polka, and I could probably learn to like it...
but whatever instruments are used, whatever style it is, if the lyrics are not going to be sung by the saints and angels in heaven, I am not going to pollute my mouth, nor fill my mind with them here.
James 3:10-12 (KJV)
10 Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.
11 Doth a fountain send forth at the same place sweet water and bitter?
12 Can the fig tree, my brethren, bear olive berries? either a vine, figs? so can no fountain both yield salt water and fresh.