However, there were several disadvantages of regular CD-audio. Optical drive technology was still limited in spindle speed, so playing an audio track from the game CD meant that the system could not access data again until it stopped the track from playing. Looping, the most common form of game music, was also a problem as when the laser reached the end of a track, it had to move itself back to the beginning to start reading again causing an audible gap in playback.