Having found the on-line Guitar Tabber and remembering OHM Studio with mentions of Band-in-a-Box I went Googling for free online music program

I've looking at a few from that page and one or two seem reasonably usable ...
Looplabs has a fairly cool program set up, but as far as I can tell you must use their samples.
I registered at UJAM , you can record your own stuff I think dut their samples are 'full pieces' of music, handy if you want to create instant music.

I particularly liked Myna, it fairly easy to use and is connected to different sounds/samples libraries including SoundCloud, you should be able to make out that I had Maxdbs SoundCloud tracks open in the lower pane :



These programs are sample based editors, though I did not go deeply into it http://www.noteflight.com/ seems a very good online program if you work in written notes, the full program probably needs paying for but I just loaded the Star Trek theme midi file into the demo which it wrote out, all 36 pages ... and played it

guitar tabber works great, tnx for the link.
fooled around a bit with Myna, its fun but very limited, Ableton does include Soundcloud as well.
Guess Myna is way easier to start with though .