Depends on the musician.A pastor is considered a full time ministry in most churches and so is a song leader. However musicians are "weekend warriors" so to speak. They have full time jobs and just play for the church on Sunday. They do it for the love of the Lord, just like pastors but they aren't considered permanent full time jobs, they are volunteers and serving the church by using their gifts.
If you find someone who wants to play your church's organ for free for three services in a row every Sunday and rehearsals during the week, I don't think anyone's going to object. But the question is whether you should feel free to hire someone when the organ would be sitting quiet otherwise.
Musical training isn't cheap in terms of money or effort. Should you expect someone to devote their lives to music for free so you can have nice music in church?
If you don't have enough volunteers at your soup kitchen, would it be wrong to offer an honorarium to your volunteers in order to attract more?Should volunteers at soup kitchens get paid? Maybe but that is not why they are there.
But they didn't "receive free". Not in most cases, anyhow. My wife's church's organist trained for decades and has a degree (a Masters, IIRC) in Music Performance. That kind of training has a major cost.Matthew 10:7 As YOU go, preach, saying, The kingdom of the heavens has drawn near. 8 Cure sick people, raise up dead persons, make lepers clean, expel demons. YOU received free, give free. 9 Do not procure gold or silver or copper for YOUR girdle purses
Heck... just having an instrument to practice on is a major cost in itself. From what I hear, most places with an organ won't let beginners play it for free unless they really like the person.