Who were the 30 tyrants, and why does socrates mention these tyrants in his defense in a trial held in democratic athens?

The Thirty Tyrants were a pro-Spartan oligarchy installed in Athens after its defeat in the Peloponnesian War in 404 BCE.

Explanation:

They put an end to many of the privileges enjoyed under democracy, and reduced the number of full citizens from over 20,000 to only 3,000 of their most loyal supporters. ... But by also associating with tyrants, Socrates had unintentionally made himself appear as an enemy of democracy.

a, both were musicians during the jazz age