The Songs of the Degrees –
If I were to say there are only fifteen stages or steps we need to climb to know all that is necessary, many would hesitate. But this is the way Hezekiah saw it. He selected fifteen Psalms that told this story and grouped them, calling them “The Songs of the degrees.” He was saved out of death and given a new opportunity of life to finish his work. His life is the mother of all parables, for we see in his deliverance the freedom offered to all.
These songs are just fifteen in one hundred and fifty, but they display the treasure locked up in the extraudinary book called the Psalms. If you want to sing then become familiar with this book and you will have a sound mind.