It is a Classical Music cadence meaning somewhat slow.
The term "mezzopiano," often abbreviated as "mp," is a musical dynamic marking that indicates a moderate level of softness or quietness in the sound. It is used by composers to instruct musicians to play or sing at a volume that is softer than "mezzo forte" (moderately loud) but louder than "piano" (soft). Essentially, it provides a nuanced way to express dynamics in music.
M means mezzo. MP is mezzopiano. MF means mezzoforte. Music is not an acronym.
"Very moderate and graceful" is an English equivalent of the Italian phrase molto moderato e grazioso. The pronunciation of the masculine singular phrase regarding a music's tempo will be "MOL-to MO-dey-RA-to ey gra-TSYO-so" in Italian.