I am not sure. I think it’s a title given by the SGPC to high ranking Ragi Singhs who sing kirtan in the presence of the Guru. I might wrong. Best ask someone more knowledgeable. Sorry.
@GurjantGnosticTry these links below for live coverage from Sachkhand Hazur Sahib.
https://m.youtube.com/watch?v=V0l0Bs-LsO4
https://m.youtube.com/watch?v=ily39yucB3k