We report the rapid tuning of mid-infrared waves beyond $5\mu \mathrm{m}$ emitted in difference-frequency mixing with an electronically tuned dual-wavelength $\mathrm{Ti}:{\mathrm{Al}}_2{\mathrm{O}}_3$ laser used as a pumping source. Simultaneous rapid tuning of the dual wavelengths, which satisfy phase matching in $\mathrm{Ag}\mathrm{Ga}{\mathrm{S}}_2$ , allows rapid random access switching and continuous tuning of mid-infrared wavelengths. In random-access switching, the mid-infrared wavelength is tuned every pulse shot at a repetition rate of $1\mathrm{kHz}$ . Mid-infrared wavelengths continuously tuned from $5.2\text{to}7.2\mu \mathrm{m}$ , from $7.0\text{to}9.1\mu \mathrm{m}$ , and from $8.9\text{to}12.0\mu \mathrm{m}$ are achieved at phase-matched angles of 55°, 50°, and 45°, respectively.