New Delhi, Feb 20 (ANI): Justin Bieber has revealed that he is always working to get better. The 19-year-old Canadian pop singer, who had recently been charged with alleged DUI in Miami and alleged assault in Toronto, tweeted that he is focusing on his music and is busy with "dance rehearsals, guitar practice, workouts, voice strengthening and studio writing sessions. He added that he believes that he needs to work hard in order to "Be great" and also professed his love for his mother Pattie Mallette.