17th-century accompaniments avoid duplicating the dissonances present in solo parts. This is borne out in available written-out versions (composer's copies, orchestral scorings), e.g. by R. Dowland, Cesti, A. Scarlatti, and Purcell. The same is evident in unrealized accompaniments (bass lines with or without figures) if interpreted according to contemporary strictures (e.g. Rule of Octave). Following these guidelines, harmonizations are suggested for laments by Monteverdi, Cavalli, and Cesti.
"It Can “spoil all the beauty”: the Duplicating of Solo Dissonances in Seventeenth-Century Thorough-bass Accompaniment,"
Performance Practice Review:
1, Article 2.
Available at: http://scholarship.claremont.edu/ppr/vol11/iss1/2