Shift selection left/right

Your idea

A way to combine note selection duration and arrow keys to move the selection. This allows for quick fix ups and experimentation (including for transcription by ear, for the less-literate of us)

¹ I haven't observed myself using Set duration to Xth note on a selection, and I'm not sure what it could be useful for. I'd suggest disabling it for selections, as it gets confusing, when used with proposed Shift selection: before shifting, the notes are transformed, and quickly thereafter reverted (after the combo-command) in above instrument 2, bar 2 to 3).

Problem to be solved

1. Listen to playback / look at the score after note entry.
2. The whole thing needs to move a beat back.

Prior art

• Everywhere I looked, the recommended solution is to cut-paste. I do this tens of times hourly, and its inefficiency is frustrating.
• Move chord/rest right/left — it took me a while to figure out how the feature works, including changing the keyboard shortcuts. Turns out it only works in insertion mode, and only for a single chord. I went through docs as well, only worked it out with the help of https://github.com/musescore/MuseScore/issues/17477.
• Moving/Shifting selection to staff above/below is already possible.
• This is similar to text editors: alt + up/down in VSCode or Joplin. It moves the current row up/down OR all lines with selected text.

Checklist

• This request follows the guidelines for reporting issues
• I have verified that this feature request has not been logged before, by searching the issue tracker for similar requests

Start by reviewing the existing “Move chord/rest right/left” behavior and its documentation, then compare it with the selection examples and playback workflow described here. A complete change would need agreed keyboard behavior for shifting selections by beat and a decision on how “Set duration to Xth note” interacts with selections.