Sentence:  And he is bending in the wind, scooping pitch, <WSD>growling</WSD>. ... He plays his false fingers. Chokes the trumpet. He is naked. This is naked jazz. O-bop-she-bam. Never lying. Telling it like it is. 
Meaning of the word marked with <WSD> tags:  Of a wind instrument: to produce a low-pitched rumbling sound.