By Simon Evans PALM BEACH GARDENS, Florida (Reuters) - Golfers prepare for competition in many different ways and for American Russell Henley, defending champion at this week's Honda Classic, playing guitar is his preferred technique. The 25-year-old Georgian joined rock band O.A.R. on stage last Saturday at Riviera Country Club after firing a two-under 69 in the third round of the Northern Trust Open. "They were nice enough to let me play two songs with them that we had planned out Saturday after the round at Riviera and it was a blast," Henley said on Tuesday. So it is something I'll always remember." Henley claimed his second PGA Tour title at last year's Honda Classic after a four-man playoff with Northern Irishman Rory McIlroy, American Ryan Palmer and Scotland's Russell Knox. More...