Why? It's simple. I hadn't practiced.
Was it was perfectionism, laziness, fear, the caprices of an artist? Call it what you will but I choose to think of it as professionalism. If I joined the rest of the choir, I wouldn't be at my best. I've been singing long enough that not only do I know what my skill level is, I know what kind of work I need to do to maintain that skill. I've also become accustomed to giving quality performances. It's to the point where anything less just won't do. Ego has nothing to do with it. It's simply because I have a reputation to maintain. Most of my friends (and in this instance, the congregation) know that I have a lovely voice and that while I'm not a professional vocalist, I've sung at a professional level for many years. Whether they consciously realize this or not, all of them expect me to perform as such. I certainly expect it of myself.
It's an expectation that I'm trying to transfer to my writing. Granted, since I'm in the early stages of my career it's far more difficult because I'm still learning what I'm capable of and what areas of the craft I need to devote more study to. Plus, since my work isn't published yet, not very many people have had an opportunity to develop or even attain a similar expectation. I am working hard on changing the latter -- both by submitting my work to publishers and by regularly updating this blog -- but the progress is slow. In some ways it's good that I've reached that level of notoriety in another art form because I can use those experiences to keep me motivated. I can look back on my early efforts as a vocalist and know that all of the hard work I'm putting into my writing and establishing this as my chosen career will pay off. To put it simply, I've done it once and I can do it again.