LONDON ¨C Two years ago, Underworld duo Karl Hyde and Rick Smith had an epiphany. After more than three decades of working together ¡ª through some unremittingly lean early years; an epoch-defining, mega-selling turn in the 1990s; soundtracking the London Olympics opening ceremony, and a fractured and increasingly separate recent past ¡ª the pair suddenly realized a convenient truth. In touring their groundbreaking 1994 album ¡°Dubnobasswithmyheadman,¡± a record that shifted the parameters of what was possible in dance music, the two men figured out that not only did they appreciate each other, they also liked each other.

¡°It had to happen eventually,¡± Hyde, the band¡¯s engaging frontman, tells me when I meet him one Friday afternoon in a hip central London bar. ¡°And there are lots of things that have contributed to it. But the bass line is that after such a long time we have found this undiscovered connection, a symbiotic relationship that¡¯s been made clear to us. We¡¯re very different to one and another and we both cover areas that the other can¡¯t or doesn¡¯t want to or hates or whatever. But we¡¯ve realized that is a strength.¡±

It took a creative absence after 2010¡¯s ¡°Barking¡± ¡ª Hyde released two albums with Brian Eno as well as a solo effort: Smith worked with film director Dany Boyle ¡ª to draw that conclusion.