Brighella's Guitar

This guitar is brilliantly painted with triangles of bright color. While attuned, you gain an expertise die on Performance checks made with this guitar. Additionally, once per day, you may use an action to cast _bestow curse as a 5th-level spell, without spending a spell slot. However, the curse is always disadvantage on Dexterity ability checks and saving throws and each failure is followed by a slapstick sound effect.