How to play a song in loop?

[pstein]

Assume I open a playlist. I want to play now (only) one song out of the list in a loop.

How can I achieve this?

Can I store this "loop forever" preference somehow in the playlist?
I would like to avoid having to manually mark it as "loop forever" at next startup again.

[Artem]

just click the "repeat" button that placed in top area of main window