Recently, I stumbled across Linux MultiMedia Studio. Pretty cool, this. And it's free!
Since I've only just started to fiddle with the program, my work is somewhat lacking. Nevertheless, making digital music with LMMS is fairly simple. Though the program is a bit buggy at times. As always with editing programs of any kind, particularly those prone to bugginess, save the work. A lot!
Still, LMMS is pretty good about recovering the project in case a crash does occur. It wasn't as annoying as some editing software that I've actually paid the big bucks for. Probably because one wouldn't expect a costly program to crash in the first place. But mostly, LMMS doesn't crash often enough to be irritating. Also, the little bugs are pretty easy to overlook considering what you can still accomplish with the program.
Here's a wee sample of something I put together extremely quickly using only a few instruments.
I know, it isn't all that good, but one gets the idea.
If interested in this piece of software, one can download it from the open source website, SourceForge here. If you like it, you might consider supporting their project with a donation.