Jason Reynolds' original novel was written in verse, we were interested in the overlap between hip-hop and spoken word poetry.
These sources were particularly interesting to me as I investigated this history:
While this source was from a blog, it delved further back into the history than other sources I found, discussing the West African griot tradition, Langston Hughes and jazz poetry, and more leading up to the creation of hip-hop in the 1970s, which I personally found very informative.
A really great scholarly source about the hip-hop/spoken word poetry intersection
This educational resource from the Kennedy Center focuses more on hip-hop itself than the connection to spoken word poetry, but it was a very well-put-together source that gives insight into each aspect of the subculture surrounding hip-hop, including some videos.
I also read about youth spoken word poetry in the book The Room is on Fire by Susan Weinstein, which I read online via the local library. It discussed three different organizations that uplifted young poets in different cities and held competitions. While it didn't always tie directly into the hip-hop/spoken word poetry overlap, it was still an interesting read.
Interviews from Jason Reynolds discussing his writing and his background in poetry provide a wonderful insight into why the original novel is written in verse, which is a great lead-in into the musical being a hip-hop musical. You can find some interviews and a full page about Jason Reynolds here!