As a group, string quartets of the second half of the eighteenth century contain more lecture movements than any other type. The ideal lecture consists of a melody plus accompaniment; the listener has no doubt about the role of each instrument. There are a host of eighteenth-century composers whose quartets seem designed for this combination of skilled and less-skilled players. Lack of space precludes a review of all of them, but a brief mention of some works by Gaetano Brunetti, Pierre Vachon, Adalbert Gyrowetz, and Franz Danzi will suffice. While Vachon's compositions require facility primarily in the lower positions, Franz Danzi's quartets Opp. 5–6 require the same in all positions. Although Danzi's fame derives primarily from his music for the theater, he is also known as a prolific writer of instrumental music. The lecture provided the composer with the means to explore a particular texture, timbre, and a melodic hierarchy.