Billie Kay -
I have heard of "Masterwriter". From what I've read about it (and some of the screen shots I've seen of it), it appears to be very comprehensive software for songwriters. If it's affordable to you, it would no doubt be a good investment. However, it IS pretty pricey, at least from what I've seen. I saw it one place listed for around $500, if I remember correctly. It seems to me that there is a "trial" version available for download, with limited abilities. But most of the trial versions of software are usually good enough to give the user a good idea of how the software works and what the "full" version offers. Some trial versions of software either don't allow you to save anything, some don't offer all capabilities, etc, and then some even come with a trial period of usually 30 days or so.
Hope this helps!!!