There are fewer more reliable fallacies in dance music than the myth of the something-for-everyone crossover album. It’s an understandable dilemma: Dance music’s audience is circumscribed by nature, but collaborating with a plethora of guest vocalists only really works if the artist has an obviously identifiable sound, like the Chemical Brothers or Basement Jaxx. The party-ready electro-house of London’s The Count And Sinden is close to that ideal—the wobbling bass of the irresistible 2008 hit, “Beeper” pushed the duo to prominence for good reason. On Mega Mega Mega, they expand on that template: “Mega” features a cute, cheesy robot voice intoning the title over B-movie synth-strings, “Panther” is hooked by a flat-sounding accordion riff (right in line with dance music’s recent penchant for Gypsy-ish instrumentation), and “Desert Rhythm” runs a spaghetti-Western guitar in parallel with high, tweeting synths and dubbed-up ambulance sirens. The problem is all the guest vocalists: For the most part, collaborators like indie-rockers the Mystery Jets (“After Dark”) and frat-rappers Trackademics (“Do You Really Want It”) sound intrusive rather than like part of the fabric. Only on “Hold Me,” with effervescent Londoner Katy B neatly negotiating woodblock percussion and wow-and-fizzle synths, do The Count And Sinden’s collaborations really take off.