A prior study of short-time time-reversal showed sideband modulation occurs for short time durations, creating overtones for single sinusoid signals. In this paper, we examine the overtones created by short-time time-reversal and the tonal relation between the overtones and the input signal. We present three methods of using short-time time-reversal for harmonizing audio signals. Then modifications to the previous short-time time-reversal needed to implement the proposed methods are described.