MuseScore 4 and Muse Sounds are now available to download via the Muse Hub installer utility. To get Muse Hub, use the main "Free Download" link on the homepage. Once installed, Muse Hub lives in the System Tray on Windows (press Windows key+B to focus) or the Status Menus / Menu Extras on macOS (press VO+M twice to focus while VoiceOver is running). Use Muse Hub to download MuseScore 4 and Muse Sounds.
Alternatively, if you just want MuseScore 4 by itself, you can use the link on the homepage labelled "Download MuseScore without Muse Hub". If you download it this way, MuseScore 4 will use the same basic instrument sounds as MuseScore 3. You could try this method if Muse Hub isn't working for you, or if you don't have enough disk space to install the sounds (the sounds take up 15 GB in total but you don't have to install all of the instruments).
Keyboard users should be aware that navigation in MuseScore 4 relies on the arrow keys in addition to the tab key. Press the tab key to cycle through each control group, then use the arrow keys to navigate to individual controls within the group. For more details, please refer to the Handbook page on Accessibility.
For all users upgrading from MuseScore 3, we recommend that you keep MuseScore 3 installed alongside MuseScore 4 until you are fully committed to the new version. Once a score has been saved with MuseScore 4, it cannot be opened again in MuseScore 3 unless you convert it to MusicXML first, which is not recommended. Also, some features from MuseScore 3 are not yet available in MuseScore 4. Please bear these points in mind when editing older scores and sharing them with other users.
MuseScore 4 Handbook
The handbook covers most aspects of how to use the program. Keyboard usage is mentioned throughout, but the following pages are particularly relevant:
MuseScore 3 users should refer to the MuseScore 3 Handbook and its Accessibility page.
Ask the MuseScore community for near-instant help! First do a site search to check whether your question has been asked and answered before.
Playlist of video tutorials by Mastering MuseScore.
Written tutorials for MuseScore 4:
MuseScore 3 users can watch this video tutorial, and follow these written tutorials: