The SABC on Wednesday afternoon confirmed that it had enforced a new rule that all of its radio stations use 90 percent local music across the board.

While the decision has been hailed by industry experts and musicians as a historic moment for local South African music, insiders tell us that there are concerns for big commercial radio stations like 5FM and Metro FM.

Not just that, but that the stations had not been informed of the decision and only found out "pretty much when the public announcement was made."

"Management wasn't told. It was already in the public space when an email informing them of the decision was sent out. It created chaos," says one insider.

Because no-one was told, there was no time to plan for the next day when the quota was to be enforced. "They had already created playlists for the next day and had no time to plan properly."

Questions about why 5FM and Metro had not adhered to the imposed quota sprung up on social media on Thursday as it seemed like nothing had changed.

"The stations use a lot of local music anyway. While everybody thinks that it is a great idea, getting that amount of music at the same quality across the board is a concern. There's also concerns around shows like The Top 40, which is a chart list of international and local music."

There was speculation that 5FM and Metro were exempt from the quota, but the public broadcaster has dismissed those rumours, also hitting back at concerns over music quality.