Very interesting:

Bard poetry differs from other poetry mainly in being sung with simple guitar accompaniment as opposed to being spoken. Another difference is that it focuses less on style and more on meaning. This means that fewer stylistic devices are used, and the poetry is often in the form of a narrative. What separates bard poetry from other songs is that the music is far less important than the lyrics; chord progressions are often very simple and tend to repeat from one bard song to another. A far more obvious difference is the commerce-free nature of the genre; songs are written to be sung and not to be sold, as the bards are often working professionals in a non-musical occupation.