A mechanical or electromechanical recording in which the groove modulation is perpendicular to the motion of the recording medium and parallel to its surface.
"I was very pleased with the results. I understand that the quality of what I sent you was quite poor and the CDs you returned represent an amazing improvement indeed. The crackling and static were gone! I appreciate your significant extra effort in producing it. I sent my Mom a copy. She was thoroughly pleased. She was even able to hear ..."