(a) The obligation of a party to pay the instrument is discharged as stated in this title or by an act or agreement with the party which would discharge an obligation to pay money under a simple contract.
(b) Discharge of the obligation of a party is not effective against a person acquiring rights of a holder in due course of the instrument without notice of the discharge.
Code 1950, §§ 6-367, 6-368, 6-409, 6-472 through 6-474; 1964, c. 219, §§ 8.3-305, 8.3-601, 8.3-602; 1992, c. 693.