Alter ability

[Marthian]

I am confused on certain archetypes.

There are archetypes that say they alter a class ability. Does anyone know what it means?

example: Dawnflower Dervish:

A Dawnflower dervish is trained in the use of the Perform skill, especially dance, to create magical effects on himself. This works like bardic performance, except that the Dawnflower dervish’s performances grant double their normal bonuses, but these bonuses only affect him. He does not need to be able to see or hear his own performance. Battle dancing is treated as bardic performance for the purposes of feats, abilities, and effects that affect bardic performance, except that battle dancing does not benefit from the Lingering Performance feat or any other ability that allows a bardic performance to grant bonuses after it has ended. The benefits of battle dancing apply only when the bard is wearing light or no armor. Like bardic performance, battle dancing cannot be maintained at the same time as other performance abilities.

Starting a battle dance is a move action, but it can be maintained each round as a free action. Changing a battle dance from one effect to another requires the Dawnflower dervish to stop the previous performance and start the new one as a move action. Like a bard, a Dawnflower dervish’s performance ends immediately if he is killed, paralyzed, stunned, knocked unconscious, or otherwise prevented from taking a free action each round. A Dawnflower dervish cannot perform more than one battle dance at a time. At 10th level, a Dawnflower dervish can start a battle dance as a swift action instead of a move action.

When the Dawnflower dervish uses the inspire courage, inspire greatness, or inspire heroics bardic performance types as battle dances, these performance types only provide benefit to the Dawnflower dervish himself. All other types of bardic performance work normally (affecting the bard and his allies, or the bard’s enemies, as appropriate).

This ability alters the standard bardic performance ability.

From reading it, it sounds like you could still use regular performance.

[SlimGauge]

I did a search of the message boards. The most common interpretation is that a Dawnflower Dervish can use only the Battledance version of Inspire Courage, Inspire Greatness and Inspire Heroics, but can use the other Bardic Performances (Countersong, Distraction, Fascination, Inspire Competence, Suggestion, Soothing Performance and Frightening Tune (and any others that are obtained by some other means)) as usual, affecting the bard and allies at normal strength.

See specifically this post by James Jacobs.