Am I obligated to report a change to the consecration (additonal songs or prayers sung/spoken by the priest) to the Bishop if the priest is aware that what he is doing is not approved? Is it a sin of omission if I do not report it, especially since it involves the consecration?
Additional songs or prayers sung or spoken by the priest during the consecration, doesn’t necessarily affect the validity of the consecration. The required formula for a valid consecration is explained as follows:
“The [standard Roman Rite] formula of consecration of the bread is: “This is my Body which will be given up for you”; of the wine: “This is the cup of my Blood, the Blood of the new and everlasting Covenant. It will be shed for you and for all so that sins may be forgiven.” The words which precede these formulas in no way pertain to the validity of the formula. It is commonly taught today that the essential words of the formula of the Eucharist—and their omission would invalidate the form—are: “This is my Body,” “This is the cup of my Blood” (or pronounce the entire formula; if any of the words from “the Blood of the new…” on are omitted, the whole formula is to be repeated conditionally” [Mass Confusion pg. 119].
If you determine that the Eucharist was not confected, you are not obligated to report it, but you should. The seriousness of this abuse should never be underestimated or minimized. For, without a validly confected Eucharist, there is no Mass, and that means no one receives the Body and Blood of Christ.