If you are paid as an independent contractor (and issued a Form 1099-MISC you can deduct these expenses.) If you are an employee and issued a Form W-2 these expenses are not deductible on your federal return, but may be deductible on your state return.
Even as an independent contractor, travel expenses from your home to your main place of work (the church), are never deductible, whether for rehearsals, regular services or special services. That is your normal commute. Travel expenses to other concert sites or churches would be deductible.
Volunteer expenses, including mileage, are deductible as a charitable contribution. Enter as a cash contribution. Mileage, including mileage from your home to and from the first church, is deductible at the 14 cents/mile charity rate; not the 58 cent business rate.
Charitable deductions are only an itemized deduction. Until all you itemized deduction exceed your standard deduction ($12,200 single, $24,400 Married filing Jointly) you will see no benefit. Itemized deductions are instead of the standard deduction, not in addition to it.
If you are a paid music director, see the other replies.