The Indy Adult Show Choir

I've always been obsessed with dancing and singing.  When I moved back to Indiana, a friend I have known since high school asked me to go to a show choir competition with him.  From that day forward, I swore we were going to start a group of people that were going to do show choir for fun! 
A couple of years later, we started working on it.  Then, one day at dinner with friends, we found a place we could rehearse. The next mission was to find people to sing with us!  We created a Facebook page for the chior, and started inviting everyone we knew.  Then, they started inviting everyone they knew. 
We had our first rehearsal, and abouth 20 people attended.  We sang through a bunch of music.  As rehearsals went on, we started having less and less people.  We learned a couple songs and learned choreography.  The main problem was, so many people were in community theater and kept doing shows.  I could never get a show scheduled for our group that didn't conflict with something us.  We finally took a break for summer.
D. and I came back after summer, and we decided we would hold auditions.  We felt bad doing that, but thought that would encourage more commitment from people.  Two people showed up.  Those two people are actually still in the choir to this day.  Then, we went from there.  We had a whole four or five people in the choir.  Then, we decided to do more advertising.  More people came and dissappeared.  Finally, I ended up with a mostly consistant group of ten.  Then, D. decided that, with the family issues he had going on in his life, he couldn't be involved anymore.  From that night on, I became the groups choreographer, also.  We did finally make it to our first performance last December.  We had about sixty people show up and watch us! 
After the Holidays, we started again in January.  We started preparing for our Spring Show.  Again, there was the interesting dynamic of people showing up in the begining to see what we are, and as the song says, We are Who We are.  People wouldn't come back.  We again had a consistant group of eleven.  Then, a couple things happenned, and we were down to nine.  We did our Spring Show a couple weeks ago with the nine, and again, had about sixty people show up!
We are again on Summer Hiatus.  We will start again on September the 1st!  My question is, how do I find people that aren't involved in community theater that have a higher commitment level?  We meet once a week, until the couple weeks before the show.  It's not that much of a commitment! Really!  I've tried different outlets of finding people.  A lot of people show up and expect it to be like high school show choir.  It's not.  It's just a fun group that gets together to dance and sing.  We have fun doing it! 
We advertise on web sites like, Facebook, Indymommashup, Craigslist, Indianaaudtions, we have our own blog, ect.  Where else is there to advertise something like this?  I've also tried to connect with one of the other local community choir people in town, who said he would send people my direction.  I didn't hear anything from him after that.  We also did flyers and papered Mass Ave. and Starbucks all around town.  That's actually where a few of my people came from last year. 
The thing is, right around the time I started really advertising for the choir, a local radio station DJ decided to start his own choir.  So, I couldn't call that station and advertise. 
How can I make this choir grow?  I also need a consistant accompanist that would play on a volunteer basis. 
Any Ideas?  I'm open!