Music composition programs

I am shortly going to purchase the new ASUS eeePC900 which comes with either Linux or XP Home. I prefer the Linux version but am using Music Time, a Windows notation program to connect my MIDI keyboard to the computer and compose music.

Does anyone know if there is a similar program under Linux?
If there is none, would someone know if I can install Windows XP Home on a USB HD and then use Music Time on the Linux computer?

I'd sure appreciate any advice or help in these matters.

Thanks,

Stuartp77