Build it and 'they' will come. The movie Field of Dreams was based on that idea that the hero hears a voice telling him to build it and he will come, he being Shoeless Joe Jackson (I bet he never thought a restaurant would be named after him).
Often we think that if we have a great program, we will never have a problem getting our members to attend practices and gigs. Well in short, that is just not so. There are many reasons why people don't show up and most of them have absolutely nothing to do with you, your program or their enjoyment of being in the choir.
1. Your singers have a life. It may be a surprise to you but your singers have a life outside the choir. They have children who get sick, and parents, partners and dogs who need attention. Some people let life dictate their timetable and so you will not see them when they are admonished for going out yet again. They may love choir once they get there but getting there through the minefield of home stuff and personalities may present difficulties.
2. They might really be sick. Enough said. In that case, please stay home.
3. Personality conflicts. There may be friction between singers. When you have dedicated people they can get very upset by others who don't see things the same way. Sometimes, sharp words can be exchanged. You really do have to to have moles they will keep their finger on the pulse of the singers. If you have a large group, this can be the job of the section leaders. Personal private discussions are sometimes a necessity.
4. Don't take it personally. You really must not think what you think people are thinking when they really aren't thinking that at all. If you are concerned that something is wrong, ask. You can ask some of your key people or make it a general question and ask for private feed back by note or e-mail. They can be anonymous if they wish. Remember each person has different view of the world never mind the choir and what happens there.
5. Don't focus on the negative. You have created (or someone has) a great singing tradition. When only a few show up, work with them Honour them. We had a small turn out for choir last practice and the sound was amazing. We sang through songs we hadn't done in a long time. We didn't focus on who wasn't there but those who were. Man they were awesome. Go with the good and be elated at the result.
Sometimes, the cat throws up on your shoe, and you just have to deal. It is never as bad as you imagine. In fact, it can be a great thing.