Four music streaming services have teamed to appeal a 44 per cent rise in royalty fees to be imposed by the US Copyright Royalty Board. If unsuccessful, it could seriously damage their ability to offer free streaming options.

Spotify, Google and US service Pandora have issued a joint statement, while Amazon is also part of the appeal group: "The Copyright Royalty Board (CRB), in a split decision, recently issued the US mechanical statutory rates in a manner that raises serious procedural and substantive concerns," it reads.

"If left to stand, the CRB’s decision harms both music licensees and copyright owners. Accordingly, we are asking the US Court of Appeals for the DC Circuit to review the decision."

Apple has not appealed the decision, reportedly because its Apple Music service is the only one that does not offer a free variant.

The CRB decision was actually made last year, but wasn't published until February 2019. It gave services 30 days to appeal from publication, which is why the joint group have only now been able to act.

The current proposal will see royalty rates rise by 43.8 per cent over the next five years, which could also result in subscription fees for services also rise to match. That will invariably annoy consumers.

While, the new appeal against the decision has also riled the songwriting community: "When the Music Modernization Act became law, there was hope it signaled a new day of improved relations between digital music services and songwriters," said the CEO of the US National Music Publishers Association, David Israelite, in a statement received by Variety.

"That hope was snuffed out today when Spotify and Amazon decided to sue songwriters in a shameful attempt to cut their payments by nearly one-third.

"No amount of insincere and hollow public relations gestures such as throwing parties or buying billboards of congratulations or naming songwriters 'geniuses' can hide the fact that these big tech bullies do not respect or value the songwriters who make their businesses possible."

It is likely the appeal process will take a while to be resolved.