You are skilled at one form of entertainment, from singing to acting to playing an instrument. Like Craft, Knowledge, and Profession, Perform is actually a number of separate skills. You could have several Perform skills, each with its own ranks.
Each of the nine categories of the Perform skill includes a variety of methods, instruments, or techniques, a small sample of which is provided for each category below.
You can impress audiences with your talent and skill in your chosen performance type.
A masterwork musical instrument gives you a +2 circumstance bonus on all Perform checks that involve its use.
Varies. Trying to earn money by playing in public requires anywhere from an evening's work to a full day's performance. The bard's special Perform-based abilities are described in that class's description.
Yes. Retries are allowed, but they don't negate previous failures, and an audience that has been unimpressed in the past is likely to be prejudiced against future performances. (Increase the DC by 2 for each previous failure.)
A bard must have ranks in specific Perform categories to use some of his Bardic Performance abilities.