If the guest singers make $600 or more in the calendar year, then yes, they should receive a 1099-misc. If the guest singers are a corporation, then you do not need to regardless of the amount.
If you paid them, and intend to take the payments as a tax deduction or expense for the year, then yes, you need to file either a 1099 or W-2 for income.
You need to give a 1099 form to guest singers if they receive more than $ 600 in a calendar year from your church. You will need to have them fill out a W 9 form with their tax information and keep a copy for your records.
Whether or not you give 1099 forms to guest singers depends on whether or not they were paid for their services. If you paid them, then yes. If not or their services were volunteered, no.