Love this thread!
Right now I have three songs that I think about in relation to therapy.

"Suitcases" by Dara Maclean
"You can't run when you're holding suitcases
It's a new day, throw away your mistakes, and open up your heart
Lay down your guard, you don't have to be afraid."

This one makes me think about opening up to T and being free of the past.

"Blessings" by Laura Story
" 'Cause what if Your blessings come through raindrops
What if Your healing comes through tears
And what if a thousand sleepless nights
Are what it takes to know You’re near
What if my greatest disappointments
Or the aching of this life
Is the revealing of a greater thirst this world can’t satisfy
And what if trials of this life
The rain, the storms, the hardest nights
Are Your mercies in disguise"

This is one I like to listen to when I am really struggling and sad.

"The Wishing Tree" by The King's Singers
"And though I am poisoned
choking on the small change
of human hope, gently
beaten into me, look
I am still alive;
in fact, in bud."

This is actually a poem by Kathleen Jamie that's been set to music. It's a wonderfully complex song that I use when I am having anxiety issues. I try to follow one singer's voice through the entire song to help regain my focus. The last line of the poem reminds me of perseverance.