Hey guys

I am a guitarist that is just looking for a program to do recording on. I currently use some opensource program to record the tracks seperate, like guitar and voice and maybe percussion... but now I need some program on PC that I can make some piano or trumpets on ... nothing too hectic, I am just looking to make some demos, and not let it sound like utter bull...

Is there a program out there that will enable me to write music using my normal PC keyboard, as I have no money for a midi keyboard...

Thanks in advance