You can play works for the flute or violin on the oboe. However, you may need to edit the music a bit to make sure it fits within the oboe's range. For example, the oboe can go up to the G an octave above the staff. The flute can go up to a D above that, and the violin can reach an A above the flute. Violins can also play down to a G below the staff, while oboes go to a B or Bb.