Here is another example of a melody in monophonic texture. First, listen to the melody excerpt below and notice the horizontal relationship which exists from note to note.
Next, listen to the melody sung by a choir, and follow the notes. Because you hear a melody alone, it is monophonic texture.
Finaly, listen to the same melody performed in octaves. The printed notation looks deceptively like more than one musical voice is present, but in fact, only one melody is being performed. Notice that the notes on both staves have the same letter names. Since only a single melody is present, we consider this to be monophonic texture.