There has been no shortage of bad ideas in the contemporary music scene. In fact, in a world where “Do you ever feel like a plastic bag?” is considered poetry, Coldplay’s “Mylo Xyloto” must have seemed like a stroke of genius. An entire album about two kids living in a post-apocalyptic wasteland! Brilliant! And we can name them Mylo and Xyloto! And just to make things weirder, we can throw some Rihanna into the mix! What could possibly go wrong?

According to Coldplay frontman Chris Martin, their new album “Mylo Xyloto,” released Oct. 24, signifies a fresh start — a blank slate upon which to begin anew. They are looking for a new direction. They are experimenting.

But Coldplay’s experimentation is only taking them further and further away from the right direction. “Mylo Xyloto” is a far cry from Coldplay’s golden days — from masterpieces like “Parachutes” and “A Rush of Blood to the Head.” Unlike those earlier, more acoustic albums, their latest record layers on the synthesizers. The result is a confused riot of sounds that never leave a real impact on the listener.

Take, for example, the three singles from “Mylo Xyloto” that have thus far been released: “Every Teardrop is a Waterfall,” “Paradise,” and “Princess of China.” The strangest thing is that they are all upbeat, danceable melodies. Whatever happened to insightful, thoughtful, slightly depressing Coldplay? Whatever happened to good Coldplay?

It is almost a certain fact that the only good Coldplay songs are the sad ones. “Mylo Xyloto” never quite brings the melancholy. “Every Teardrop is a Waterfall” sounds promising, yes, but in reality, it’s just about a bunch of British teens who like to party all night. Or maybe it’s about Mylo and Xyloto partying all night. Either way, the song consists of a list of generalizations stapled together and taped to a background of overly chaotic Chilean guitar riffs. Nobody is going to cry here, except maybe in pain.

“Paradise,” again, displays Coldplay’s taste for the dramatic. It was intriguing during “Viva la Vida,” from the album of the same name, but now it’s just getting a little annoying. Cut the sweeping, cinematic “oohs” and “aahs.” And those synthesizers!

And “Princess of China” features Rihanna. It is not necessary to elaborate on everything wrong with that picture.

It is as if Coldplay has sacrificed making quality music in order to make big bucks. They have given up their gentle melodies in favor of radio-friendly tunes, and their willingness to feature pop princess Rihanna — whose sound is impossibly incompatible with traditional Coldplay songs — only illustrates how far they have sold out.

However, “Mylo Xyloto” does have its moments. “Charlie Brown,” again an ode to rebelling teenagers, pulls off the feat in a manner far superior to that of “Every Teardrop is a Waterfall.” While both are fast-paced, “Charlie Brown” has a melody that is not obscured by a whole cavalcade of bass lines and drumbeats. And “Charlie” gets bonus points for having lyrics that do not make you cringe, unlike “Teardrop” with its long-winded discourses on punctuation (“I’d rather be a comma than a full stop”).

But the best song on the album is the gentle, acoustic-backed “Us Against the World.” And it provides a valuable lesson for Coldplay: “I just want to be there when the lightning strikes/And the saints go marching in,” croons Chris Martin in a voice so intimate it feels like he is whispering the words into your ear. “And sing slow-oh-oh-oh it down.”

Yes, Coldplay. Slow it down.