Final answer:
In 'Porgy and Bess,' George Gershwin uniquely incorporates blue notes, which are emblematic of the blues genre and reflect the African American experience, blending classical music with jazz and blues.
Step-by-step explanation:
One quirky thing that George Gershwin incorporates into 'Porgy and Bess' is the usage of blue notes, which are pitches that are played at a slightly lower frequency than those that are standard in the traditional Western scale. This is a characteristic feature of blues music, which Gershwin was attempting to integrate within a classical opera context to reflect the African American experience authentically.
Gershwin uses this musical technique extensively throughout the opera in a way that it blends classical music traditions with the distinctive sounds of jazz and blues, resonating with the essence of the American South and the struggles of the characters portrayed in 'Porgy and Bess'.