Quit OSCII bot (and maybe Reaper and other audio/midi related apps).
Select OSCII bot's icon in the Finder. Type Command-I (i, not L), or use the "Get info" menu item.
Check "Prevent app nap". Close window.
Think that should work in Sierra too, but don't have a Sierra machine at hand. It doesn't work in High Sierra or Mojave!
Alternatively, you can turn off app nap completely in Terminal:
Code:
defaults write NSGlobalDomain NSAppSleepDisabled -bool YES