Can you help me find an audition song for High School Musical?

Im auditioning for High School Musical, and i want the role of Martha, Kelsey, or Gabriella, but i have no clue on what to sing for my audition. Im an alto, so i have a low to medium range. PLEASE give me some song ideas. Could you match the song to the character/voice it would fit best? Thankyou so much in advance! I will choose a best answer asap!