Complex sentence: The concept of kitsch is applied to artwork that was a response to the 19th-century art with aesthetics that convey exaggerated sentimentality and melodrama, hence, "kitsch art" is closely associated with "sentimental art".
Split into simpler sentences: The concept of kitsch is applied to artwork that was a response to the 19th-century art with aesthetics that convey exaggerated sentimentality and melodrama. Hence, "kitsch art" is closely associated with "sentimental art".