Windows, toolbars and panels within MuseScore can be repositioned, and you can choose which elements you want to see displayed in them.
The default appearance of MuseScore is shown below:
To change the position of either the note input or playback toolbars, click on and hold the six dots at the left of the toolbar, then drag and drop it to the desired location. The toolbar can be left free floating, but in the case of the note input toolbar, you can also drag and drop it either to the left or the bottom edge of the program window—a blue rectange then appears to show you that you can drop the toolbar at that location to redock it. The playback toolbar can only be redocked in its default position.
To select the icons that you want on view in the note input or playback toolbars, click on the gear icon to the right of the toolbar:
In the case of the note input toolbar, this reveals a dropdown list from which you can hide or display the various icons by clicking on the eye symbol to the left of each one (closed=hidden, open=displayed).
In the case of the playback toolbar, uncheck or check the various options in the gear menu to hide or display the corresponding elements.
To undock and move one of the side panels (Palette, Instruments, Properties, or Selection filter), click on the three dots on the tab, select the Undock option, then drag the undocked panel to the desired position.
You can leave the panel free-standing but there are also dock positions at the top and right hand edges of the document window—a blue rectangle appears to show that you can drop the panel to redock it at that location.
In a similar way, you can redock the free panel back to the sidebar:
You can also redock the free panel in its original position by clicking on the three dots on the tab, and selecting Dock.
Panels such as the Mixer or virtual Piano can be undocked if desired, by dragging them into position or clicking on the three dots icon and selecting Undock. To redock, click on the three dots icon and select Dock.
The undocked mixer can be resized by dragging the edges inwards or outwards.
To customize the palettes area, see Customization: Palettes.