Is Music Haram? -

One time I was there happened to be some music playing, and I asked a Muslim, "Isn't this haram"?
Well this music is.", he replied, and mentioned all those musical instruments in the song.
I in turn pointed out that many psalms specify musical instruments that they should be played on.
Here is one example from Psalm 5.

For the Chief Musician, with the flutes. A Psalm by David.

This is not a header added by the translators but is part of the text.
The muslim opined that this was a corruption of the original text.

For me, if a verse has a footnote that says that it is not present in some manuscripts, then, my rule is that I cannot use it by itself to prove or disprove a doctrine.

For example, for 1 John 5:8 we read this note in the NIV:

Footnotes:

1. 1 John 5:8 Late manuscripts of the Vulgate testify in heaven: the Father, the Word and the Holy Spirit, and these three are one. ⁸ And there are three that testify on earth: the (not found in any Greek manuscript before the fourteenth century)

On the other hand if there is no such footnote then we have no reason to believe that the text is in dispute.  What criteria do Muslims use to decide what verse can be used and what cannot?  That is a point worth clarifying.