What is this symbol?
I play 1st oboe in my band and both me and the other player are confused on what the symbol means. The sheet music has both parts on it in the same staff, where it is one note then second part's not just below it on whatever they are playing. So we got our music and randomly throughout the piece there is a lower case a and a 2 next to it. a2. Sometimes it is in parenthesis and sometimes it isn't. If anyone knows what it means I would appreciate the help. Thanks!