The songwriters behind smash hits from Katy Perry, Bruno Mars, Britney Spears and Beyonce discuss how they wrote the hits at a roundtable event.

It came as a bit of a surprise to see the line of eager last-minute ticket buyers and attendees stretching down the block outside West Hollywood’s Key Club on Saturday. Although Cee Lo Green, Seal and the Neptunes’ Chad Hugo were inside, they weren’t performing. Instead, they were talking songwriting along with lesser-known, behind-the-scenes hit authors Bonnie McKee, BC Jean and Claude Kelly during BMI’s How I Wrote That Song panel.

The writers behind the sticky hooks and melodies that reigned in pop and R&B sat down with Grammy-winning producer Dallas Austin and BMI Vice President Catherine Brewton for an in-depth discussion on the particulars of their respective hits.

One doesn't really appreciate the potential of Bruno Mars until you see him perform in a casual setting -- like Bardot in Hollywood on Friday night, with friends, family and the famous surrounding him in the intimate room. It's here where Mars, 25, shines. Though still young, he has been a music fanatic and performer for more than two decades -- he impersonated Elvis Presley at age 4 -- and it shows from his song selection and his easy interaction with his audience. Over the course of the final 15 minutes of performance, Mars, wearing his trademark fedora, ripped through Prince's "Kiss," Little Richard's "Long Tall Sally," slipped in the occasional Bob Marley quote, before landing at Otis Redding's "Sitting on the Dock of the Bay." (This reporter arrived late -- Cee Lo Green and Big Boi were performing at Club Nokia across town, and difficult decisions had to be made -- and therefore missed the Far East Movement's performance with Mars.)