What are the important aspects of the form in the examples of Mendelssohns “Songs without Words”?
As with so many of the domestic genres (pieces written for home use) and the “character” or “characteristic” pieces, these works are often in A-B-A form or some closely related variant (this applies to the piano pieces in NAWM by Schumann). Individual details would include the A-B-A-B-A variant of Mendelssohn’s “Spinning Song” (NAWM 106b), and the embedded ternary forms in Schumann’s “Grillen” (NAWM 107a).