Looped play through while recording

I have a percussion track I’m playing over and would like it to loop rather than having to extend the track.

How do I do that?

Windows 10

Audacity 2.1.0

Apply the “Repeat” effect to the percussion track: http://manual.audacityteam.org/man/repeat.html

The current Audacity version is 2.1.2: http://www.audacityteam.org/download/windows.