The title echoes " Rheingold " ( " The Rhine Gold " , 1869 ) which is the first of four operas in Richard Wagner 's opera cycle " Der Ring des Nibelungen " .
Head entity: "rheingold" Q327717 3 4 5
Tail entity: der ring des nibelungen Q190237 29 30 31 32
Relation (head \u2192 tail): P361
Inverse relation (tail \u2192 head): P527