The Middle-Class Gentleman is a play written by Molière in the XVII century.
First of all, the play's tittle is a word play: a "gentleman" -or nobleman- is someone born in a noble or aristocratic environment, so this means that a gentleman could never come from the Middle-Class.
Furthermore, this play emphasizes how the Middle-Class started to copy the mannerisms and tastes from the aristocracy, also showing how snobbish and completely vain the aristocracy was, mixing all of these things with clever and on point humor.
To summarize, the Middle-Class wanted to copy manners coming from the aristocrats, and climb its way up the aristocratic ladder.