A bard can use his song or poetics to produce magical effects on those around him (usually including himself, if desired). While these abilities fall under the category of bardic music and the descriptions discuss singing or playing instruments, they can all be activated by reciting poetry, chanting, singing lyrical songs, singing melodies, whistling, playing an instrument, or playing an instrument in combination with some spoken performance. Each ability requires both a minimum level, and has a limited duration of time, characters can be beneficiated only by one inspiration at a time.
There isn't a skill level for this skill, the power and usefulness of it is related directly to the character level.
Each inspiration costs a "bardic music use", I would suggest playing songs costing also a "bard music use". You get X "bard Music uses" for day according your character level.
(Here is the suggestion in D&D terms)
Inspire Courage: at character level 4/16/28/40 members of their party get +1/+2/+3/+4 to hit and damage respectively.
Inspire Competence : at character level 4/22/38 members of their party
get +2/+4/+6 to their skill checks (no to their weapon combat skills)
Inspire Greatness: at character level 25 members of their party get (2D10+con modifier) of hp extra, +2 on attack rolls and +1 on fortitude rolls
Inspire Heroics: at character level 35 members of their party get +4 in all their saving rolls and +4 AC
