"Unsung" by Vanessa Carlton is a song about unrequited love and the frustration that comes with it. The speaker wishes she could understand the person she is in love with and meet their standards, but she feels like she is constantly falling short. She longs for the person to recognize her worth and value her as a treasure. However, she feels neglected and unappreciated, and her efforts go unnoticed.

The chorus emphasizes the feeling of being overshadowed and underappreciated, with the speaker waiting for any recognition or acknowledgement from the person she loves. The line "I'm only as good as the last one" implies that she feels like her worth is only measured by her last achievement or interaction with the person. The phrase "as my song goes unsung" reinforces the idea that her feelings and efforts are unheard and unappreciated, just like an unsung song.

In the second verse, the speaker is struggling with the changes in the relationship and feels like she is slipping away from the person. She is searching for a place where she can belong and feel appreciated, but she is unable to find it. The repetition of the first verse in the third verse suggests that the speaker's feelings are constant and ongoing, and she still longs to be valued and understood.

In the final chorus, the speaker conveys her desire to be the lesson that the person learns from, the one that they finally recognize and love. However, she also acknowledges the pain that comes with being the last one to be burned in the process of love. Overall, "Unsung" captures the emotional turmoil of unrequited love and the frustration of feeling unnoticed and undervalued.