The human voice is a natural instrument with unique capabilities. Speech and music have been combined since the earliest times, so that Song is probably one of the oldest musical forms. Simple definitions for song might be "a piece of music performed by voice, with or without instrumental accompaniment," or "a poem set to music." The German word for such classical song is Lied (singular) and Lieder (plural), so that you will hear the terms "art song," "lied" and "lieder" used interchangeably. In France the term is Melodie, and in Italy, Romanza.
Music enhances words with emotional energy that speech alone cannot convey. But obviously, there is more to it than this! There are vocal compositions, for example, with no articulated text at all, called vocalises or vocalizzi in Italian. Although such works traditionally have been used as exercises, some 20th century composers have written concert vocalises as well. Additionally, singing styles differ among cultures, reflecting such influences as social structures, levels of literacy, languages and even sexual mores. This has resulted in a wide variety of musical products commonly accepted as "song."
Yearning-inspired by a lost love, nature, a legend, or other times and places haunted the imagination of romantic poets. Thus art songs are filled with the despair of unrequited love; the beauty of flowers, trees, and brooks; and the supernatural happenings of folktales. There are also songs of joy, wit, and humor. But by and large, romantic song was a reaching out of the soul.
Song composers would interpret a poem, translating its mood, atmosphere, and imagery into music. They created a vocal melody that was musically satisfying and perfectly molded to the text. Important words were emphasized by stressed tones or melodic climaxes. The voice shares the interpretive task with the piano. The mood is often set by a brief piano introduction and summed up at the end by a piano section called a postlude .