Concertmate is a line of consumer-grade electronic keyboards and synthesizers sold in the 1980s and 1990s by RadioShack (Tandy Corporation), most often under the Realistic and later Optimus house brands. Rather than being an independent manufacturer, Concertmate was a model series whose instruments were primarily rebadged versions of Casio keyboards — the Concertmate 200 was a Casio VL-1, the Concertmate 300 a Casio PT-1, the Concertmate 500 a Casio SK-1, and the Concertmate 670 a Casio CA-100, among others. The line spanned simple monophonic novelties, sampling keyboards, and full arranger keyboards such as the Concertmate 950.

The most historically significant entry in the line is the Realistic Concertmate MG-1, a true analog synthesizer designed in collaboration with Moog Music and released through RadioShack from 1982 to 1983. Engineered by Paul Schreiber at Tandy and David Luce at Moog (who had previously worked on the Polymoog), the MG-1 was built down to a consumer price point, omitting pitch and modulation wheels and relabeling controls in plain language — oscillators became "Tone Source," the envelope a "Contour," ring modulation a "Bell Tone." With roughly 23,000 units sold, it became the best-selling synthesizer Moog ever produced and remains one of the most widely owned vintage Moog instruments.

When RadioShack's exclusive option on the MG-1 design expired, Moog reworked the circuit — dropping the polyphonic organ and ring modulator and adding pitch and mod wheels — to release it as the Moog Rogue. Concertmate keyboards are no longer in production and circulate primarily on the vintage market, where the MG-1 in particular has a following among analog synth enthusiasts despite a well-known issue with disintegrating black polyurethane foam insulation that can interfere with the instrument's mechanics.

Concertmate has 2 products cataloged on Equipboard, including Portable & Arranger Keyboards. Their gear is featured by 1 artist, with the strongest followings in Electronic. Notable users include OMFG.