Hanna-Barbera wanted to do two things with The Impossibles. One, as superheroes, they were another campy entry cashing in on the success of the live-action Batman, which had begun its 2nd season in the fall of 1966. The other was, as a rock group, complete with mop-top hairdos, they were another knockoff of the quintessential pop group of the period, The Beatles, whose own animated series was entering its 2nd season as well.
Sadly, the studio didn't have the foresight to release an album of Impossibles songs that were written for the show. None of their songs were ever played in their entirety, anyway. H-B corrected that oversight 2 years later with the release of an album spun from The Banana Splits, but, oh, what might've been.
The Impossibles were Coil Man (Hal Smith, The Andy Griffith Show), Fluid Man (Paul Frees, who was also the narrator and the voice of Big D, the team's government handler), and Multi-Man (Don Messick, also heard as a radio DJ and the villain in the following episode). What was really impossible about this combo was that they were all guitar players. No keyboards or drums for these guys, but in those days, not only was continuity a low priority, but the writers didn't have much attention to small details, either.
Anyway, the boys gear up for battle to rescue the youthful Shah of Shish-Kabob (Dick Beals, heard as Buzz Conroy in the Frankenstein, Jr. half of the show) from the clutches of "The Bubbler". Uploaded by Mistifal.
Well, it's better than uploading the open and listening to Frees' Orson Welles-esque reading of the theme song......