Das geheime Königreich
... that the short satirical opera Das geheime Königreich (The Secret Kingdom) by Ernst Krenek premiered in Wiesbaden in May 1928?
... that the short satirical opera <i id="mwBDU"><b id="mwBDY"><a href="./Das_geheime_Königreich" id="mwBDc" rel="mw:WikiLink" title="Das geheime Königreich">Das geheime Königreich</a></b></i> (<i id="mwBDg">The Secret Kingdom</i>) by <a href="./Ernst_Krenek" id="mwBDk" rel="mw:WikiLink" title="Ernst Krenek">Ernst Krenek</a> premiered in <a href="./Internationale_Maifestspiele_Wiesbaden" id="mwBDo" rel="mw:WikiLink" title="Internationale Maifestspiele Wiesbaden">Wiesbaden in May 1928</a>?