Lisa Hirsch linked to a clever flowchart made by an Australian composer that poses (or really spoofs) the question of whether a composer should write an orchestral piece.
Writing a piece for orchestra takes a lot of time, and there are a lot of things to pay attention to. The chance of actually hearing a humanly generated performance is rare, but sometimes writing for orchestra (even a small one) is the only way for me to say what I need to say musically.
Contrary to the intended spirit of J. M. Gerraughty's flowchart, answering his question (and cringing at the end point of each path being the phrase "shut up,") might have actually prompted me to finish a chamber orchestra piece that I have been working on (well, on and off) for 14 years. The piece earned its title this past weekend while I was working on it at 3:00 in the morning during a bout of insomnia. I have had a few things on my mind these past weeks that can only be best expressed musically.
You can listen to a computer-generated recording of it here, and see the score and parts here.