 The biographical sources are informed by Avempace’s expertise as a musician and as a composer of muwashshaha poetry. In addition, he has left us a brief composition on the  melodies[15].  Avempace expounds on the therapeutic effect of playing the ‛ud, lute, on the basis of universal harmony existing between the heavenly spheres and the bodily nature, the humors. Each chord of the lute is related to one of the four elements: fire, air, earth, water, and each chord has a beneficial influence on each disease caused by one of the humors. The chord called zir acts on the bile, the chord mathnà on the blood, the chord mathlat on the black bile, and the chord bam on the phlegm. Avempace instructs the player how to place the lute on his body and which finger plays which chord. If the musician plays the lute in the right way, his day will be most beautiful.