Pop star Rihanna was the original choice to sing on Fun.'s Grammy-winning global smash We Are Young but the band had to pick a new guest vocalist when she failed to respond to the offer.

The Bajan singer was approached by the song's producer Jeff Bhasker, who admits the Umbrella hitmaker was "kind of a muse" for the group.

However, Bhasker believes "wires got crossed" during early negotiations with Rihanna, so they chose a relative unknown, Janelle Monae, to sing on the track instead.

He tells MTV News, "(The band) said, 'Who can we get?' And I said, 'Let's get Rihanna'. We were shooting for the stars on everything and she was kind of a muse. Someone (from the record label) tried to reach out (to Rihanna) and I know she heard the song and liked it. But I think some wires just got crossed.

"But everything works out for a reason and Janelle worked out to be the perfect choice. She brought the right element of a great soulful flavor that we wanted for the album."

The pop-rockers went on to win the Song of the Year prize for the hit at Sunday's (10Feb13) Grammy Awards.