A capo for an instrument having a plurality of strings elevated above a fretboard such as a dobro, slide guitar, Hawaiian guitar, or similar raised stringed instrument. Each flanking polymer is covalently bound to an end of the core polymer and the copolymer is soluble at a level of at least 1% by weight in water at 25 C. In another embodiment, the first and second molded parts are interconnectable to define the guide groove.