Having scored an impressive 12 number one singles in just five years, Irish boy band Westlife appeared to be pretty invincible when they released of their fifth studio album, Allow Us to Be Frank, which as the title implies, is a collection of some of the most popular songs from the Rat Pack era.

However, coming just three years after Robbie Williams' similar Swing When You're Winning and the Pop Idol compilation of big-band classics, it provides more ammunition for their critics, who describe them as nothing more than the subservient puppets of Simon Cowell.

Having never expressed any interest in the genre before, Allow Us to Be Frank, clever puns aside, feels like a lazy and unimaginative cash-in from a band who, thanks to covers of tracks by Barry Manilow, Cliff Richard, and Phil Collins, aren't exactly renowned for their cutting-edge invention.

Indeed, whereas Williams' old-school effort featured Hollywood star collaborations and self-penned compositions in an effort to distance itself from the inevitable karaoke criticisms, Westlife, unsurprisingly, plays it completely safe, opting for 13 of the most iconic, if obvious, swing standards.

Backed by a 60-piece orchestra, the arrangements of "Mack the Knife," "Ain't That a Kick in the Head," and "Fly Me to the Moon" are undeniably faithful and respectful interpretations, while Filan and Feehily's best Sinatra impersonations on the likes of "Come Fly with Me" and "Moon River" aren't as cringe-worthy as you might expect.

But even though it's no disgrace, the question inevitably arises, why would anyone opt for a second-rate tribute album instead of the real thing? Whether it will inspire their millions of teenage fans to seek out the much more authentic source material remains to be seen.

But if anyone was hoping that the recent departure of Brian McFadden might reignite the spark of their earlier pure pop output, Allow Us to Be Frank confirms that Westlife are now more at ease plundering their parents' record collection than offering anything remotely original.