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I also think king saul should maybe be considered. in 1 samuel 10:5-10, it talks about saul prophesying with musicians and praising the lord. if he has the Prophet identifier from this one time he prophesied, he should have the musician identifier as well. plus, barak is a musician and he only sang one song, so why not saul?
Per the REG singing a song isn't the same as being a musician (which would mean I am because I sing songs but Lord knows I'm no musician!). They would of had to have led a group of people in singing and worship, wrote songs, or those in the Bible who were described as being a musician by profession.
Where is there a song in Daniel 3?