Okay, I know "Hart to Hart" is supposed to be this light-hearted detective comedy. And it is, it's VERY light hearted. In fact, it's usually pretty silly, so if you watch this, you know what you're getting. But they have strained credibility too far! They expect us to believe that Jennifer Hart (Stefanie Powers's) "favourite" opera is from Richard Wagner's "Der Ring des Nibelungen"?! That's just a bridge too far. Now, if they had used "La Boheme," or "La Traviata," or "Carmen," THAT I could believe. Or "Lucia di Lammermoor," "Tosca," or "The Barber of Seville." Or even some of the lesser-known, but highly melodic, operas like "La Rondine," "Pêcheurs de Perles," or "Don Carlo." But, no, they pick The Ring Cycle. Sheesh!
On a side note, have you noticed how quickly they get over all the deaths that occur, even of people who are friends or acquaintances of theirs? Very cold. (Yes, I know, light-hearted comedy. It just struck me when their helpful friend, Lieutenant Andy Kirkson, blew up instead of Jonathan Hart (Robert Wagner), the intended victim, and they continued onward without a pause.)