Habakkuk and the Orchestra

There is this passage at the end of Habakkuk:

Although the fig tree shall not blossom, neither shall fruit be in the vines; the labour of the olive shall fail, and the fields shall yield no meat; the flock shall be cut off from the fold, and there shall be no herd in the stalls:

Yet I will rejoice in the LORD, I will joy in the God of my salvation.

I read it for my morning devotion yesterday, and something struck me as I was listening to the Malaysian Philharmonic Orchestra at night; what happens when a musician isn't up to the task?

Do musicians treat performances as merely 'work', or are they constantly influenced and affected by their emotions? Can a conductor passionately command a performance of a lively and heroic piece, though choked by the news of the death of a loved one?

I look at the near 100 musicians (on average) on stage, and surely not all of them are having a great time; they all feel different emotions, have different experiences, and undergo different trials. And yet, when they come together, the music feels so united, almost as though they were all one, literally.

Is it possible for us to actually, realistically say, "My life is screwed up, yet I will rejoice in the Lord..."? Though all of our efforts fail, and there's no reason to go on believing, can we still carry on? If we can, then how? And if we know how, will we?