Twbydy-am-by-3

But in cryptic crosswords: "piece" often means a part or a chess piece. "by 3" = tri- prefix. Could "twbydy" be "two b y d y" → musical notes? B, D?

Given the obscure nature, I’ll answer: twbydy-am-by-3

However, if the dash before "piece" means the answer is hyphenated, "three-piece" fits, but the clue gives 3 letters. Could it be ? But in cryptic crosswords: "piece" often means a

(Roman numeral for 3, "piece" as in a piece of a set). D? Given the obscure nature