The author uses the example of the Philadelphia clubwoman to illustrate what problem in Negro culture that holds artists back?

From the text:

A prominent Negro clubwoman in Philadelphia paid eleven dollars to hear Raquel Meller sing Andalusian popular songs. But she told me a few weeks before she would not think of going to hear "that woman," Clara Smith, a great black artist, sing Negro folksongs. And many an upper -class Negro church, even now, would not dream of employing a spiritual in its services. The drab melodies in white folks' hymnbooks are much to be preferred. "We want to worship the Lord correctly and quietly. We don't believe in 'shouting.' Let's be dull like the Nordics," they say, in effect.

The problem addressed in this section is conformity, giving up or turning one's back on one's culture. As a result, African American artists are held back.