He shall feed His flock

The choir concert is this Sunday afternoon. I am singing the alto solo"O Thou, That Tellest Good Tidings" and the first part of "He Shall Feed His Flock". I tend to get nervous singing alone in front of people. However, since I will be holding music, I don't think it will be too bad. I hope it won't be bad - b/c "O Thou" is a freaking LONG solo and I don't want my voice to get shaky anytime during it.