Odyssey Arena, Belfast. Mon 8pm £35/£33 048-90739074

BRITNEY SPEARS

O2, Dublin Mon 8pm 91.25/70.70/54.80 0818-719300; Odyssey Arena, Belfast Tues 8pm £80/£65/£55 048-90739074

Fight Club! In the risque corner we have Katy Perry, one of the perkiest, smartest and popular American pop stars of the past few years. No stranger to controversy (she kissed a girl and she liked it) and comedy (the name’s Brand, Russell Brand), Perry has outshone her opponents in recent times by virtue of a record-breaking sequence of 52 consecutive weeks in the top 10 of the

Billboard

Hot 100 charts. Katy’s fragrance is called Purr and comes in a cat-shaped bottle. She’s ranked 7th in

Rolling Stone’s

Queen of Pop poll.

In the risky corner we have Britney Spears, who, following a period of time in the Lost Cause Celeb Zone, has made a startling about-face in popularity. Her latest album, Femme Fatale,has brought her right back into commercial focus, effortlessly adding to her 100 million record sales worldwide. Britney is a serial fragrance endorser and has, with the likes of fragrances such as Curious, Fantasy and Believe, become the No 1 celebrity perfume-endorser of all time, with a gross of $1.5 billion.

Result? Britney might smell better, but Katy has better pop music kudos and, for what it’s worth, credibility. Perry also has a personality. Which helps.

Can't see that? Catch this

James Vincent McMorrow Fri/Sat, Dublin; Tues, Cork