The church cannot always provide the cash needed for these expenses, so some choir fundraising is definitely in order if you want to make sure that your choir can keep performing at full power.
Choir fundraising can take many forms, but one of the most popular and successful ways to bring in money is to organize a concert at the church to benefit the choir and its members. At your choir concert, you'll want to make sure you're making the most out of the opportunities you have. There is a room full of eager supporters, and of course you'll have the price of their tickets to help out, but that's not all you can be doing. As long as people are there anyway, you can make use of the fact that the choir won't be singing the entire time.
During the intermission, you can have food and drinks available, as well as inviting people to stay and talk to the choir and buy even more food afterward. There's also nothing preventing you from having some supplementary fundraisers at your choir concert, but you'll need to think about which ones would work best. You'll probably want to stick with direct sales fundraisers for your choir fundraiser event - there is such a large array of direct sale fundraisers out there that you could have several going on at the same time. This also increases the chances that people will see something that catches their attention, and this in turn will raise the profit level for you, and more importantly, for the choir.