: A complete translation by Rodolphe d'Erlanger, Grand traité de la musique , is often used by scholars and can be found in some digital libraries .
If you do not need the full medieval text but rather an explanation of the theory, these articles are excellent and freely available. kitab almusiqa alkabir english pdf link
: Al-Farabi shifted the rhythm. The melody became light, mirroring the "perfect circles" of the stars he wrote about. The merchant found himself laughing, his weariness forgotten as if the sun had risen inside his chest. : A complete translation by Rodolphe d'Erlanger, Grand
For those looking for the source text to use with translation tools, a complete scan is available on the Internet Archive . Grand traité de la musique