"I can't play my songs on the smaller harp. I have a Celtic harp. I can't do the key changes"

This quote by Joanna Newsom is referring to the difficulty of playing her tunes on a smaller sized harp. She is particularly describing a Celtic harp, which is a type of harp that is bigger than the typical harp. The problem depends on the truth that the smaller harp does not have the variety of notes that the larger harp has, making it difficult to do key changes. This is an issue for Joanna Newsom, as her songs often need crucial modifications in order to be played correctly. By stating that she can't do the crucial changes, she is suggesting that the smaller harp is not ideal for playing her songs. This quote is a testimony to the value of having the best instrument for the job, as the smaller sized harp is simply not capable of playing her songs as they were meant.