The first note

An original fiction passage set in the nineteenth century.

Clara stood behind the curtain while the audience settled. The piano waited beneath the lamps, its polished lid catching the light. She had practised the opening until she could play it without looking at the keys. Now the tune would not come to her. She pressed her thumb against the edge of the music, then listened as the room fell quiet. When the curtain began to move, she drew one breath and stepped forward.

Identify the words that show Clara has lost confidence just before her performance.