Rod Stewart struggles to make love to fiancée Penny Lancaster if there's music playing in the background.The 61-year-old rocker has confessed he finds it difficult to concentrate on the job in hand if he can hear a song playing, and admits he needs to concentrate a lot more in the bedroom than he did when he was younger. Rod, who is a renowned womaniser, told British radio station Heart: "I'm not one for having music on, or the TV, or any distractions for that matter. I just like a few candles around the place otherwise I lose my concentration. To be a good lover takes great concentration. Penny is a lucky lady, but I'm also a very lucky man. She's heaven sent."Rod is not the only male star who cannot perform between the sheets if there is music playing. Justin Timberlake recently admitted he can't make love to girlfriend Cameron Diaz if he can hear a song playing - because he loses his focus. He said: "I have trouble having sex to music because I'll start picking out the chords."