Conductors are a relatively new breed of musician. Only as compositions became more complex circa 1810 (blame Beethoven!) did the actual need for a conductor become more relevant. Conductors were in demand pre-Beethoven, but to a far lesser degree.
As the noted author and music critic Norman Lebrecht has alluded to in his book “The Maestro Myth,” there remains considerable mystique surrounding conductors, despite the fact that thousands of performance recordings showing conductors “face-on” are now available online. One such example is Sir Simon Rattle conducting Gustav Mahler’s 2nd symphony.