Original sentence: Etudes can be in many forms and are sometimes grouped into larger schemes - Robert Schumann's Études symphoniques bears the title, in its second version, Études en forme de Variations.For example, Frédéric Chopin's etude Op.In contrast, Czerny's are generally regarded by pianists and audiences as being only technically difficult
Edited sentence: For example, Frederic Chopin's etude Op.In contrast, Czerny's are only technically difficult