If a werewolf in hybrid form, who has class levels in bard, starts performing with howls, growls, and other wolf noises, (with ranks in oration) does the party still gain benefits?
Or put simpler, if a bard sings in a language the rest of the party doesn't understand, do they still gain benefit?
I think Oratory is probably the only Perform that might not work if the party couldn't understand you. I'd be inclined to say that it still does, though, since the Distraction performance is allowed to be done with Oratory but relies on visual components - you clearly don't need to understand the story to benefit from the visual aspect.
For the record, Oratory is a visual performance:
Distraction (Su): At 1st level, a bard can use his performance to counter magic effects that depend on sight. Each round of the Distraction, he makes a Perform (act, comedy, dance, or oratory) skill check. Any creature within 30 feet of the bard (including the bard himself) that is affected by an illusion (pattern) or illusion (figment) magical attack may use the bard’s Perform check result in place of its saving throw if, after the saving throw is rolled, the Perform check result proves to be higher. If a creature within range of the Distraction is already under the effect of a non-instantaneous illusion (pattern) or illusion (figment) magical attack, it gains another saving throw against the effect each round it sees the Distraction, but it must use the bard’s Perform check result for the save. Distraction does not work on effects that don’t allow saves. Distraction relies on visual components.
So you can only use Oratory for performances that rely on visual and not auditory components (unless it allows either/or).
Secondly, and to the original poster's question, the performance must say that it is language-dependent for that to matter:
For example:
Suggestion (Sp): A bard of 6th level or higher can use his performance to make a suggestion (as per the spell) to a creature that he has already fascinated (see above). Using this ability does not disrupt the fascinate effect, but it does require a standard action to activate (in addition to the free action to continue the fascinate effect). A bard can use this ability more than once against an individual creature during an individual performance.
A Will saving throw (DC 10 + 1/2 bard’s level + bard’s Cha modifier) negates the effect. This ability affects only a single creature (but see mass suggestion, below). Suggestion is an enchantment (compulsion), mind-affecting, language-dependent ability and relies on audible components.
So, if a werewolf bard was doing a performance in wolf form, they could use Inspire Courage and Frightening Tune, but not Suggestion.