Do forgive me for being tardy with this post, but I thought I ought to include it for completness' sake :-)

In Act IV Scene ii, Sir Anthony begins to sing Youth's the Season from John Gay’s famous work, The Beggar's Opera.

In The Beggar's Opera this song is actually sung by the highwayman, Macheath, surrounded by a chorus of his whores. I'm not sure what exactly was Sheriden's intent here: but this speech by Sir Anthony combined with this song again gives me an uncomfortable feeling about Sir Anthony and his amourous feelings.

The song he sings comes from Act II.Scene iv, (Air xxii).

Here are the lyrics:

Youth's the Season made for Joys,
Love is then our Duty,
She alone who that employs,
Well deserves her Beauty.
Let's be gay,
While we may,
Beauty's a Flower, despis'd in decay.

(Chorus) Youth's the Season, &c.
Let us drink and sport to-day,
Ours is not tomorrow.
Love with Youth flies swift, away,
Age is nought but Sorrow.
Dance and sing,
Time's on the Wing,
Life never knows the return of Spring.

Just for illustrative purposes , here is a famous Hogarth painting of the principal characters in that opera, now owned by Tate Britain.

This picture depicts the climactic scene in The Beggar’s Opera, which was first performed at the Lincoln’s Inn Theatre in 1728.

Here the opera’s central character, Macheath, stands chained, under sentence of death, between his two lovers, the jailer’s daughter, Lucy Lockit, and, to the right, the lawyer’s daughter, Polly Peachum.

They in turn plead for his life. At either side of the stage Hogarth has included members of the audience, notably at the far right the Duke of Bolton, real-life lover of the actress, Lavinia Fenton