Tenn. Code Ann. § 9-22-104

The grant of a pledge or the creation of a lien on collateral by an issuer, which grant or creation is otherwise authorized under Tennessee law, shall be valid and binding from the time that the pledge or lien is created or granted and shall inure to the benefit of the holder or holders of the public obligations with respect to which such pledge or lien was created or granted until the payment in full of the principal thereof and premium and interest thereon, and neither the official action nor any other instrument granting, creating, or giving notice of the pledge or lien need be publicly filed or recorded to preserve, protect or perfect the validity or priority of such pledge or lien.