The chief characteristic of Erart's poetry is his preference for short lines, mostly penta-, hexa-, hepta-, and octosyllabic, as opposed to the traditional decasyllable, which does occur in his chansons "Pré ne vergier ne boscaige foillu" and "Encoire sui cil ki a merchi s'atent" and his serventois "Nus chanters".For a more detailed description of his metres, see Mary O'Neill (2006), Courtly Love Songs of Medieval France: Transmission and Style in the Trouvère Repertoire (Oxford: Oxford University Press), 134–5, with notes 8–12. Musically, Erart is syllabic, with a preference for major modes and refrains. His chansons are composed mainly in isometre, but his pastourelles are predominantly heterometric. His music is conservative and rarely exceeds a ninth in range.
