If you are not convinced that a CD is capable of perfectly reproducing a sound wave then watch the video on the page below. The performance of a CD is measured on an oscilloscope and compared to the performance of an LP. The CD reproduces the 1KHz and 15KHz sine waves perfectly. The LP cannot match this accuracy and that is why you are able to hear noticeable harmonic distortion no matter what quality of sound reproduction equipment you are using.
http://www.harbeth.co.uk/usergroup/showthread.php?2046-An-honest-appraisal-of-vinyl-v-digital-romance-v-reality/page10
