They waited. That was always the worst part, the waiting. Waiting meant time to think about what could happen. Waiting meant wondering if it was going to sound right, even though that was foolish; they'd checked and rechecked to make sure they were ready. Waiting meant wondering if the audience was even in the right mood for the music, even though once they started, they could shift the mood easily enough. Waiting meant wondering if Pinkie Pie was there, even though... To be fair, that one could change the course of the evening. Eventually, the wait was over. The crowd grew quiet in anticipation. There was no more time for wondering. It was time. They started the music.
Immediately, their worries were gone, replaced by the music. This was the moment they lived for, the chance to bare their souls to the audience through the music they played. As they played, they watched the audience for their response. Musical performance was more interactive than many realized; everything they did worked with the audience that night, and were the music listened to anywhere else, at any other time, it wouldn't be quite right. But that night, working with the crowd, gradually shifting their mood with the music they played, it was perfect.
They smiled. As always, they had performed impeccably. The crowd had responded exactly as they had wanted to everything they'd played. It was almost time. They held the note, giving the audience that much more time to absorb the emotion.
She lowered the bow from her cello, and applause filled the sudden silence.
She dropped the bass, and the crowd went wild.