Do the USFSA rules allow Lyrics with No Music (i.e. acapella)?

[Neverdull44]

Do the USFSA rules allow Lyrics with No Music (i.e. acapella)?  I found a great piece of music that I want to use.  It's 1:36, all acapella.   I am going to mix in another piece of music that is :20 that has some musical instruments in it.   

[Query]

I won't answer your question, but you probably know:

"A Cappella" or "A Capella" is music with no instruments, which may or may not have lyrics.
Rap is words with no music.

[Doubletoe]

Is there singing with a melody?  Or is it just spoken word?  I don't know if plain spoken word (i.e., not music) is allowed, but actual "a capella" singing would be allowed for sure.  The human voice has always been considered a musical instrument; the only difference is that now the human voices are allowed to sing actual words as well.