It hurts to say this, but Live Aid should not be celebrated. It was a failure. Geldof's approach exemplified the worst about Western ideas of "helping Africa": top-down handouts which ignore, or worsen, the continent's problems.
The real cause of the 1984 Ethiopian famine, and so many other African tragedies, was not cruel nature, but bad government: the country was torn by civil war. That is what stopped food getting through. There is substantial evidence that charitable intervention, Geldof's included, may have prolonged and deepened the conflict, and therefore the catastrophe.