In the late 1990s, Konami's Bemani division was synonymous with music games, dominating the Japanese arcade scene to the point where its name became a catch-all term for the entire genre. Rhythm games of a form, in truth they were really more like Simon Says elevated to the level of performance art.
Whether it was kids strutting their stuff to Dance Dance Revolution at the Trocadero or a salaryman cathartically taking out the frustrations of a long workday by slapping the primary-coloured buttons of a Pop 'N' Music cabinet, seeing someone play these games well was a genuine thrill. Those dancing hands or dancing feet were evidence that here was someone who had dedicated hour upon hour overcoming the monolithic challenge of truly mastering these games.
Bemani suffered a rapid decline, partly through oversaturation, but also as music games moved from the arcade to the home console, but it's enjoyed a bit of a revival on smartphones lately. Multi-touch screens might lack the satisfying click of those lovely big arcade buttons, but are otherwise the perfect interface for the genre, and so it's hardly surprising we've seen portable versions of Jubeat and DDR.