Medley and melee are the same word — one mixes songs peacefully, the other mixes fighters violently, but both mean "a mixed-up mess."
A varied mixture or assortment, or a musical composition combining several songs or tunes.
From Anglo-French medlee meaning a mix or melee, from Old French meslee meaning mixed, mingled, past participle of mesler meaning to mix Key roots: miscēre (Latin: "to mix").