Alicia Keys practices yoga to calm her nerves.The 'Girl on Fire' singer will perform the American national anthem before the Super Bowl XLVII in New Orleans tonight (03.02.13) and revealed she got lots of sleep and did yogawith her personal trainer to help her relax before the event.The 32-year-old star shared her pre-performance ritual with her fans on Twitter this morning, saying: "Jus finished a beautiful, calming yoga session. My intention is 2 enjoy everypiece of this special day! What's urs? (sic)"She also admitted that she is very excited about performing at the event.She said: "The energy is so amazing! u can feel it all over! I feel excited in a way I'm not sure I ever have! :-) can't wait!!"Getting ready to sing my heart out for America! The city is electric!!"The mother-of-one - who is married to music producer Swizz Beatz and has a one-year-old son Egypt - will perform the 'Star Spangled Banner' before the game.Her good pal Jennifer Hudson is also performing 'America the Beautiful' at the event and she shared a picture of them rehearsing together earlier today.Jennifer, 31, revealed her performance will be extra special for her as she is performing alongside children from Sandy Hook elementary school in Newtown, Connecticut, where 20children and six adults were killed by a shooter in December.She tweeted: "Such a privilege to be performing w the Sandy Hook elementary chorus at the #SuperBowl today. We go on just before kick off!"Earlier this week Beyonce - who is performing the half-time show - admitted she makes love to her husband Jay-Z to help her relax.She said: "When I get nervous or I don't have everything together I like to make love to my husband."Their performances tonight could be seen by over 150 million people around the world, and the singer admitted those feelings of nerves will be creeping in.The 'Love On Top' hitmaker added: "I've been preparing for five months for this moment. I'm happy I'll have my husband there with me - it's every woman's dream to feel this wayabout her husband."The singer has been married to rapper Jay-Z since April 2008, and the couple welcomed daughter Blue Ivy into the world January last year.