Backstreet may not be back, but the boy band trend certainly is, with British group One Direction’s new album debuting at No. 1 on the Billboard charts. But when the Style team was putting together Thursday’s package about the return of the boy band, there was some debate over who would be included in the photo gallery chronicling the genre below.

View Photo Gallery: Current chart-topping pop acts One Direction, The Wanted and Big Time Rush follow in a proud tradition of boy bands.

You’ll notice some popular groups missing. Where’s Hanson? The Jonas Brothers? Can a band be a boy band if the members are related? Most of all, can a boy band play instruments?

Traditionally, the answer to the latter question is no. Boy bands are more about slick dance moves and pre-packaged good looks, rather than musical talent beyond vocals. Though members of boy bands often can play instruments, it’s not really part of their act to do so — unless they blur the line between boy band and actual band, as the brothers Hanson and Jonas have. This leaves them off of some boy band lists, for better or worse.

Melinda Newman wrote about three new boy bands for Post — One Direction, The Wanted and Big Time Rush — and the instrument question came up, putting one band’s manager on defense:

The Wanted’s manager, Scooter Braun, who also handles Justin Bieber’s career, stresses that they can play instruments, although that skill is not remotely on display in the video for “Glad You Came,” which focuses more on the five members’ abilities to doff their shirts and be stared at adoringly.

Boy bands are often criticized for not playing instruments, but this isn’t something we come to expect from all of our solo pop stars, so why must they bear the brunt of that criticism? It’s also something that can make boy band members self-conscious: Often, when it’s time for them to “grow up” into solo careers, they emphasize that they can play instruments and produce or write songs, in order to distance themselves in their next career phase.

The gentlemen of One Direction, The Wanted and Big Time Rush may be a long time away from that — right now, they’re riding high on No. 1 singles, TV appearances and the sound of their own voices, but without musical instruments in their hands.