9. It Saved The Universe Once
Yes. You did read that right. The basics of 'The Three Doctors' are as follows- there's three of them for the first ever multi-Doctor adventure. Omega ( a legendary figure from Gallifrey's past) returns and isn't very happy. And yes, the recorder does indeed save the day. Huzzah! But how? Is he lulled by its twinkly tones? Quite. Well..not quite. There's some science involved. And while nasty old Omega does indeed lay hands on the prized instrument it quickly proves a big mistake on his part. By touching an object charged with energy from 'our' universe having dwelled in a pocket one of his own creation it becomes apparent the bonkers stellar engineer might do himself a mischief. It does mean the Second Doctor needs a new recorder at the end of it all. Still at least there are some positives - he's managed to demonstrate his undoubted mastery by playing 'Twinkle Twinkle Little Star'. Curiously this seems to annoy his later self but never mind.