I have tried a number of music score editors. The one that I like that is light weight, and easy to use is nted, the only problem is if you do complex music arrangements with it it crashes.
But for simple music arrangements, it works great, you just need to remember you can't add more than one instrument to one staff. This is what causes the editor to crash.
The items I have added so far to the respin.
- Aconnectgui
Asunder CD ripper
Audacity
gtklick
Guayadeque Music player
Muse
nted
Openshot Video editor
QjackCtl
QjackRcd
Timidity++ MIDI sequencer
Virtual MIDI keyboard
VLC player
XBMC
XMMS