I usually carry set of CD's. 1. Instrumental (Ilayaraja and A.R. Rahman) 2. Melody Songs (Ilayaraja and A.R Rahman) 3. Fast beat songs (any music director, 80's to latest and this includes some of the Hindi songs. Latest addition to this is "Lungi Dance" from Chennai Express ) 4. Old songs (70's to 80's) If I feel sleepy, I play the fast beat songs otherwise, I will go one of the other CD's.