Does a Skald's Raging Song prevent spellcasting?

Question

This is the description of the Skald's Raging Song (Su) class feature:

If a raging song affects allies, when the skald begins a raging song and at the start of each ally’s turn in which they can hear the raging song, the skald’s allies must decide whether to accept or refuse its effects. This is not an action. Unconscious allies automatically accept the song. If accepted, the raging song’s effects last for that ally’s turn or until the song ends, whichever comes first.

[...]

While under the effects of inspired rage, allies other than the skald cannot use any Charisma-, Dexterity-, or Intelligence-based skills (except Acrobatics, Fly, Intimidate, and Ride) or any ability that requires patience or concentration.

Does it prevent spellcasting?

The d20pfsrd entry has a link on the word "concentration" going to the Concentration Rules for spellcasters. But if read on paper, you could argue whether "an ability that requires concentration" equals spellcasting or whether you would need a Concentration Check to cast a spell while under the influence of a Raging Song.

Answer 1

Raging Song (Inspired Rage only¹) should prevent spellcasting

The argument I will use for this statement is comparing the wording that is on the Bloodrager's Bloodrage ability:

While bloodraging, a bloodrager cannot use any Charisma-, Dexterity-, or Intelligence-based skills (except Acrobatics, Fly, Intimidate, and Ride) or any ability that requires patience or concentration.

Notice the wording is very similar to the Skald's Inspired Rage. Further, there is nothing else on the description of Bloodrage stating that no spellcasting is allowed. Now the Bloodrager, at level 4 gains the Blood Casting ability (emphasis mine):

At 4th level, the bloodrager gains the ability to cast spells even while bloodraging. He can also cast these spells defensively and can make concentration checks for these spells while bloodraging. While bloodraging, he can cast and concentrate on only his bloodrager spells (see below); spells from other classes cannot be cast during this state.

This seems to imply that normally a Bloodrager would be unable to cast during Bloodrage (or this feature would not make much sense).

Since the Bloodrage ability and Inspired Rage use very similar wording one can conclude that the Inspired Rage Raging Song should also not allow spellcasting.

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^{1. Stolen from ShadowKras' answer, who was the one who noticed only Inspired Rage in particular had that effect}

Answer 2

Yes, but only for Inspired Rage

The other songs lack that restriction entirely, so that is only valid for their first song, ,Inspired Rage. But yes, since spellcasting requires concentration, if you are under the effects of the song, you cannot cast spells.

This was even joked about during the playtest of the class:

*This does mean no spellcasting, correct?*

It's the same language as barbarian rage. If you're using the Advanced Class Guide and you still don't know that spellcasting requires concentration, I can't help ya. :)

That is, for anyone listening to be inspired rage song that is not the Skald himself:

While under the effects of inspired rage, allies other than the skald cannot use any Charisma-, Dexterity-, or Intelligence-based skills (except Acrobatics, Fly, Intimidate, and Ride) or any ability that requires patience or concentration.