"a song to be performed by one singer and one pianist that contains good poetry set to music." this definition describes the

This definition best describes what is known as an Art Song.

Art Song is a musical composition created for a piano and one singer in the classical musical tradition. This needs to be distinguished from other types of songs for example a songs that use other instruments other than the piano and the songs that appear in operas or musicals. In German language these songs are known as Lied and in French as Melodie.

The answer is colored light