I think you can make the bx from the middle
An orchestra is defined as a large instrumental ensemble typical of classical music. An orchestra features bass, brass, strings, woodwinds, and percussions. In the list given above, the section that is not one of the four groups in the orchestral palette is the voices. The answer would be "voices".
I am not too sure whether there were some options, but there is something I have heard about: giving classes or teaching.
Very often when you read about the lives of the musicians, you hear them teaching the rich and often being flustrated at having to do it; since the rich are not onlways talented. But they need to do it to close their budget.