I'd say make 4 basic types of bards

Jesters - mostly do negative things to enemies. Main abilities are based around confusion.

Skald - Beefy guys. These warchanters are tough as nails and like to be in the thick of it. Their songs usually boost their own and their parties combat ability.

Soloist - Their songs are powerful, but usually only benefit themselves.

Something - Defensive songs, they bring hope to their party members and use songs defensively.