To share a score with someone who's not on MuseScore, go to the score page on musescore.com and click the big 'Share' button on the right of the webpage (or in the three-dotted menu on the upper right in the mobile app). This will provide you with different options:
Buttons to post the score directly to your social media account(s): Facebook, Pinterest, Tumblr, or Twitter.
The page's URL, which you can copy and paste into a message.
Embed code, so you can make the score actually appear and play in the middle of your blog or web page.
If you click the share button on one of your own private scores, the URL you get (and which is used in the embed code and posted on the social media) is a "secret link" that will allow people to view your score even though it is private. You can also reset the secret link, which will make an earlier secret link no longer work.
In mobile app
In the mobile app, the ⋮ icon in the top right corner exposes the Download, Favorite, and Share buttons.
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