I get so confused about slurs and ties. Of course I know the rule that slurs connect different notes and ties connect the same notes.
Argument for the lower line being a tie:
The lines connect the same notes.
Argument for the lower line being a slur:
The chord introduces new notes (E, G), making it part of a new group.
A tie would not make musical sense here as the chord needs to be played in full.
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... feeling like the pianist on the Titanic ...