Boys united: Singers of US bands New Kids on the Block and Backstreet Boys perform in a sold-out joint concert in Ancol, Jakarta, on Friday. —JP/Jerry AdigunaThe joint forces of New Kids on the Block (NKOTB) and Backstreet Boys (BSB), hit-makers from the final decades of last century, transported fans back in time to their heyday with an entertaining and highly energetic show.

The nine guys may be older now, but judging from the deafening screams inside the packed Mata Elang International Stadium (MEIS) in Ancol, North Jakarta, they have yet to lose their ability to charm their fans in Indonesia.

The night was surely a big bash and a nostalgia fiesta as the show included two generations. For some, it was like going back to 1989 again, while for others, it was a trip to 1999.

The concert-goers, who were mostly 20- and 30-something females, had gotten older also si...