This study investigated the effects of therapeutic singing as an intervention for improving the vocal functions of the elderly. Data collection for this study took place at five senior community centers in Seoul, South Korea, from August 2018 to March 2019. A total of 54 elderly with healthy voices were assigned to a therapeutic singing group, a general singing group, or a control group, using convenience sampling. The therapeutic singing intervention involved using the Alexander technique, performing oral motor and respiratory exercises, and singing participant-written songs, across 12 sessions. The general singing group sang popular and folk songs of their choice. The control group received no treatment. Using peak expiratory flow rate (PEF) and Praat analysis, the participants' vocal functions were measured before and immediately after the intervention. Vocal function was compared among the groups pre- and post-test; the therapeutic singing group showed statistically significant improvement in all vocal parameters: PEF, maximum phonation time, voice intensity (intensity), fundamental frequency (F0), jitter, shimmer, and noise-to harmonics ratio. The general singing group showed improvement only in F0, jitter, and noise-to harmonics ratio. The control group showed an overall reduction in all vocal functions, with a significant decrease in PEF and intensity, and a decrease in jitter and shimmer. Although singing is considered helpful for the voice health of the elderly, therapeutic singing, which involves posture correction and breathing exercises, is even more effective, thus proving to be a viable intervention for preventive voice care of the elderly.