The Flaming Lips have done way too much in their glorious 3½ decades to make the kind of prog-rock that revels in the genre’s worst tendencies. At their best, the band create dreamy slices of spaced-out neo-psychedelica distinguished by indelible pop melodies and a sense of childlike wonderment.

It’s sad, then, that King’s Mouth – a concept record to accompany an art exhibition by frontman Wayne Coyne – slides into the realm of parody. The madcap lyrics – including regular spoken word interludes featuring The Clash’s Mick Jones and the story of a king whose head is severed and cast in steel – are proggy silliness and feel perfunctory when compared to the Lips’ once-gripping flair for surreal lyricism.

The songs themselves lack form, while the vocals often feel totally untethered from the instrumentation without creating a juxtaposition that’s in any way interesting.

And when the band aren’t doing obvious Pink Floyd pastiches (Dipped in Steel, for example), the arrangements can be sloppy – Feedaloodum Beedle Dot sees keyboards bumping into guitar lines like two drunken strangers on a dancefloor.

Originally dropped as a Record Store Day exclusive, King’s Mouth probably should have been spared a wider release, leaving it as a curio in the band’s undeniably brilliant body of work.