Musescore upgrade for ubuntu

You can do the steps graphically. See an example here: http://askubuntu.com/a/5102
The ppa you have to add is this one:
ppa:mscore-ubuntu/mscore-stable
So the steps are:
1- add and enable the mscore-stable ppa as described in the link; note that for newer version of Ubuntu than the one described in the link the Software Sources dialog should be in "Software & Updates" and not in Software Center (Open Unity Dash and search for Software & Updates)
2- install/upgrade MuseScore via the Software Center

Ciao,
ABL

ABL's method works fine, but you would probably find this is much faster in the terminal, if you wanted to try it.

Simply copy the following lines (all in one go), paste them into the terminal and hit Enter on your keyboard.

sudo add-apt-repository ppa:mscore-ubuntu/mscore-stable
sudo apt-get update
sudo apt-get install musescore

You will be prompted for your password because installing software requires "root" (admin) privileges.

Notes:

• Use Ctrl+Shift+V to paste in the terminal, not Ctrl+V
• When you type your password no characters will be displayed (not even asterisks ****). This is a security feature.

You might find this tutorial series on YouTube useful if you want to learn more about the Linux terminal.